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Frog Dragon
2009-06-30, 05:38 AM
So. Since I'm planning on including a red dragon lair in my game, I looked up the heat dangers rules and apparently 140 Fahrenheit is a lethal temperature. this translates to roughly 60 Celcius.
I go to sauna two times a week. It is warmed to about 80 Celcius and I can tell from personal experience that it is not even close to harmful even if you sit there for a few minutes.
So what's up with the heat rules then which seem to hold the position that two minutes in a sauna should knock you unconscious and three more minutes, kill you. WTF is up with that?

AslanCross
2009-06-30, 05:39 AM
Try wearing full plate and fight for your survival against a giant monster for a minute inside the sauna.

Yuki Akuma
2009-06-30, 06:06 AM
Heck, try doing anything other than sitting around being lazy in that sort of temperature.

Also, the steam actually does help. If you were in that sort of temperature without the steam, you'd be a lot less comfortable.

Frog Dragon
2009-06-30, 06:10 AM
the rules show no mention of distinction on what you're doing and in what clothing. plus 60 Celcius is way too low a limit anyway.

And comfortable of not, it's still no justification for lethal damage. There is a vast gap between not comfrotable and lethal conditions.

Nero24200
2009-06-30, 06:20 AM
What if you sit there for a few hours? Clearing a dungeon that hot is never going to take only a few minutes.

Riva
2009-06-30, 06:22 AM
Did you know that 134 F (adjusted for humidity) is considered the temperature that lethal heat sickness comes into play? Like for job safety and stuff? So that temperature is literally lethal.

Furthermore, this is a really ridiculous nitpick. They picked a temperature that is actually harmful, I say good show.

BooNL
2009-06-30, 06:24 AM
The rules do mentions minutes, not hours.

I frequently visit the sauna, with temperatures ranging from 80 to 102 Celcius. And yes, 102 is fracking hot, I can't stand it for more than a couple of minutes, but I frequently spend more than half an hour in 95 degrees saunas. No biggie there.

Ofcourse, you're naked and lounging around but still...

AvatarZero
2009-06-30, 06:32 AM
And comfortable of not, it's still no justification for lethal damage.

That may be why it doesn't. Heat dangers don't deal lethal damage unless you actually pass out from exposure.


Heat deals nonlethal damage that cannot be recovered until the character gets cooled off (reaches shade, survives until nightfall, gets doused in water, is targeted by endure elements, and so forth). Once rendered unconscious through the accumulation of nonlethal damage, the character begins to take lethal damage at the same rate.

When you're covered in steam you can stay cool as hot water evaporates off you, so an eighty degree sauna is no danger to you, but if your core temperature ever got to 40 you'd be in serious danger of death. A desert is a very different situation. The Sahara is a distinctly lethal desert for unprepared travelers, and at it's hottest it doesn't often reach 130 Fahrenheit or about 55 Celsius.

I've never been in a desert, but I reckon the 3.5 rules do a decent job. Here's an article on overheating (http://en.wikipedia.org/wiki/Hyperthermia) if you're interested.

cloneof
2009-06-30, 06:53 AM
Alright, I tested it.

Me and my buddy went to 90 Celcius Sauna and throwed a small ball for an hour, while wearing t-shirts, jeans etc... and Cookwares on our heads.

It made me thirsty, but nothing lethal.

Fixer
2009-06-30, 06:56 AM
If you actually take a measurement of the AIR TEMPERATURE I doubt, severely, it would be 80 to 102 Celsius. That is likely the temperature of whatever is creating the steam. At 100 degrees Celsius air temperature, all the water vaporizes into steam, including whatever sweat happens to be on your skin or whatever you happen to breathe out.

You know what, just check out THIS TABLE (http://www.cqcapd.state.ny.us/newsletter/estime.htm). That is how long you can last at the various temperatures before your skin blackens and chars off of you due to 3rd degree burns.

Estimated Times/Temperatures Causing a Full Thickness (third degree) Burn in Children/Adults

For Adults

If the temperature is 160 degrees fahrenheit, it would take 1 second [to cause a third degree burn];
If the temperature is 149 degrees fahrenheit [common home boiler setting], it would take 2 seconds;
If the temperature is 140 degrees, it would take 5 seconds;
If the temperature is 133 degrees, it would take 16 seconds;
If the temperature is 130 degrees [recommended setting], it would take 35 seconds;
If the temperature is 127 degrees, it would take 1 minute;
If the temperature is 125 degrees, it would take 2 minutes;
If the temperature is 124 degrees, it would take 3 minutes;
If the temperature is 120 degrees, it would take 10 minutes.
[Adult skin thickness of 2.5mm]

For Children:

If the temperature is 160 degrees fahrenheit, it would take less than 1 second [to cause a third degree burn];
If the temperature is 149 degrees fahrenheit [common home boiler setting], it would take .5 seconds;
If the temperature is 140 degrees, it would take 1 second;
If the temperature is 135 degrees, it would take 4 seconds;
If the temperature is 130 degrees, it would take 10 seconds.
[Child skin thickness of 0.56mm]
Date from National Burn Victim Foundation


Now, these are for water temperature. Water moves heat faster than air so if the AIR was that hot, you could last longer but not indefinitely.

AslanCross
2009-06-30, 06:57 AM
Okay, looking at the rules:



A character in very hot conditions (above 90° F) must make a Fortitude saving throw each hour (DC 15, +1 for each previous check) or take 1d4 points of nonlethal damage. Characters wearing heavy clothing or armor of any sort take a -4 penalty on their saves. A character with the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well. Characters reduced to unconsciousness begin taking lethal damage (1d4 points per hour).

Okay, I guess the OP is right, in a way. This is rather ridiculous. The temperature in this country is routinely beyond 90° F (32° C), usually worse indoors due to lack of sufficient ventilation. Today's temperature was 33° C. I spent the first half of the day walking back and forth between classrooms, carrying heavy loads. While it was pretty freaking exhausting, it wasn't enough to knock me out. Or maybe I made my Fort saves. (For reference: I am of Asian descent, have a height of 5'8", weigh 163 lbs, and exercise regularly.)



In severe heat (above 110° F), a character must make a Fortitude save once every 10 minutes (DC 15, +1 for each previous check) or take 1d4 points of nonlethal damage. Characters wearing heavy clothing or armor of any sort take a -4 penalty on their saves. A character with the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well. Characters reduced to unconsciousness begin taking lethal damage (1d4 points per each 10-minute period).

A character who takes any nonlethal damage from heat exposure now suffers from heatstroke and is fatigued.

These penalties end when the character recovers the nonlethal damage she took from the heat.

Okay, it's never been that hot here in my experience. I would think that unless one is accustomed to such temperatures, even sitting still is going to become very uncomfortable very quickly. Note, however, that there are Fort saves to be made. Noteworthy is the penalty imposed by heavy clothing or armor of any kind. I'd think the only person in a party who wouldn't have this penalty is the monk.

It's kind of weird that they used the heatstroke nomenclature, though. Heatstroke is a life-threatening condition that results in imminent death if not treated quickly. On the other hand, I'd think



Extreme heat (air temperature over 140° F, fire, boiling water, lava) deals lethal damage. Breathing air in these temperatures deals 1d6 points of damage per minute (no save). In addition, a character must make a Fortitude save every 5 minutes (DC 15, +1 per previous check) or take 1d4 points of nonlethal damage. Those wearing heavy clothing or any sort of armor take a -4 penalty on their saves. In addition, those wearing metal armor or coming into contact with very hot metal are affected as if by a heat metal spell.

140°F/60° C is pretty damn hot. I've never been to a sauna (the people who use the sauna in the gym are slightly scary to sit with in a dim room), but as has been mentioned, I'm pretty sure the steam actually makes it bearable.

I still cannot see a fully-clothed person (most adventurers are) remaining in such conditions for long, even if they're just sitting around talking. A wizard surely wouldn't be able to prepare spells without protection (which he's likely to have anyway). I definitely would impose this damage if combat broke out in such an environment.

Note that the lava and fire mentioned here seem to only be the heat you get from being close to them. Further down in the Environment entry you see damage from actually being on fire/immersed in lava. I'd stack the damage from both the exposure to the hot air and the actual immersion.

Anyway, OP, if the temperatures really trouble you, you could always just raise them.

Mitth'raw'nuruo
2009-06-30, 07:30 AM
In severe heat (above 110° F), a character must make a Fortitude save once every 10 minutes (DC 15, +1 for each previous check) or take 1d4 points of nonlethal damage. Characters wearing heavy clothing or armor of any sort take a -4 penalty on their saves. A character with the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well. Characters reduced to unconsciousness begin taking lethal damage (1d4 points per each 10-minute period).

A character who takes any nonlethal damage from heat exposure now suffers from heatstroke and is fatigued.

These penalties end when the character recovers the nonlethal damage she took from the heat.

I am in Iraq right now, I am a combat medic. I wear 60 pounds of gear every day and am dismounted (walking around) frequently. In an hour I probabily drink 2 L of water a bottle of to replace electrolytes, no to mention forcing myself to eat hearty meals. Been here since January, so I am about as acclimatized as it gets for someone of European decent. One of our biggest enemies is the heat. This is reflected in the bonus given by the survival skill IE being prepared.

As a DM I would give a much larger bonus to someone who rolled the check before being exposed to a hot environment and took the requited equipment then to someone who thought about it after the fact.

For example: you need to protect your eyes from the sun (sunglasses, blacking ink under the eyes). You should not let skin exposed, paints, long selves or a robe are a must (sunburn, and if you burn your skin losses the ability to regulate you body temperature. Sunburn can lead directly to heat stroke)

You do not run in this heat. Not with body armour. Doing anything more physical then walking, and you are risking a failed fort save. The temperature have been around 120 or so, without factoring in humidity (which makes it "hotter" as sweating is less effective at removing heat from the body - the opposite of the sauna theory seen on the forums.)


The rules are correct. If you were thirsty you were taking non-leatheal damage. The fact that you even got thirsty was a danger sign. Stay in that sana until you pass and and unless somebody saves you; you are going to die. That fact is not up for debate.

People die from heat stroke all the time; in temperatures lower then 140. But fixer posted a lovely temperature chart. Any time the body's ability to cool it self is over whelemed you risk serious injury and dealth from total organ failure.

Heat exhaustion is when the body is still able to attempt to compensate. Symptoms include nausea, vomiting fatigue, headache, dizziness.

Heat stroke is when the body has failed to compensate for the heat. A "classic" sign is the absence of sweating, with hot red or flushed dry skin, but this is seen in less then 50% of cases. More often you see:
Seizures
Coma
Death
hallucinations
difficulty breathing
rapid pulse (dehydration)
agitation/confusion.

You can not "test" this by sitting in a sauna. It is a well established medical fact, and if anything the rules in D&D are liberal. The body likes to hang out @ at core temp of between 97 and 99 degrees depending on the person. If that temperature climbs to 105-106-107-108, death is going to happen very soon unless immediate & dramatic intervention happens. I am talking interavenious fluids (preferably chilled), removing of clothing, dousing in water and application of ice to groin/armpits/neck, and removal for heated environment.

Yuki Akuma
2009-06-30, 07:38 AM
A sauna is more bearable than the equivalent dry heat - because you're not being blasted by pure dry heat and all the water in the air does help conduct heat away from your body much better than dry air does. Plus, you're not as likely to dehydrate with all that steam (although you'll dehydrate eventually, just not quite as fast).

A sauna isn't just 'humid'.

Random832
2009-06-30, 07:43 AM
A sauna is more bearable than the equivalent dry heat - because you're not being blasted by pure dry heat and all the water in the air does help conduct heat away from your body much better than dry air does.

Wait :smallconfused: if the air is hotter than your body temperature, wouldn't the water help conduct heat towards your body, not away from it?

ImmortalAer
2009-06-30, 07:50 AM
Wait :smallconfused: if the air is hotter than your body temperature, wouldn't the water help conduct heat towards your body, not away from it?

But not all the water sticks to you, and the individual droplets cool and then warm again from the rest that are coming up behind it (removing that ambient heat from the air), so the swirls of mist are actually absorbing heat and letting you feel it in a nice warm (...or burning.) fog.

Yuki Akuma
2009-06-30, 07:54 AM
But not all the water sticks to you, and the individual droplets cool and then warm again from the rest that are coming up behind it (removing that ambient heat from the air), so the swirls of mist are actually absorbing heat and letting you feel it in a nice warm (...or burning.) fog.

More or less.

A sauna's heat distribution is far more complex than the equivalent block of metal, say.

Draxonicar
2009-06-30, 08:02 AM
More or less.

A sauna's heat distribution is far more complex than the equivalent block of metal, say.
....Or breath of fire from a dragon..

ImmortalAer
2009-06-30, 08:04 AM
....Or breath of fire from a dragon..

Well of course, because a breath of fire lights you on fire!

...except in Soviet Russia. But we're not getting into that.

pjackson
2009-06-30, 08:21 AM
On a holiday in Egypt several years ago, one day it was 113F at 9am. We spent 30 minutes looking around a couple of temples that were on the river bank. I was not the only one who was ill for the rest of the day, despite being in an air conditioned boat the rest of the time.

Zeta Kai
2009-06-30, 08:57 AM
Bottom Line: The numerical evidence (provided by the relative experts Fixer & Thrawn) indicates that the rules are a reasonable approximation of what one could expect in the real world, albeit simplified for ease of use in an actual game. The anecdotal "evidence" is deficient & scientifically unrigorous. I'm siding with the rules on this one.

There are many places where the rules don't model reality very well at all. This is not one of them. Go poke at the Diplomacy rules; those are rather borked. The Jump rules (3.5, anyway) are a bit off, too. And according to RAW, no human can run as fast as an Olympic sprinter, regardless of feats, skills, or level. Unless they are a monk. :smallconfused:

Kris Strife
2009-06-30, 08:59 AM
Eh, having been in a sauna set to 120 degrees farenheight, wearing what amounted to a pair of black plastic trash bags cut into the shape of pants and a long sleeve shirt (yes, they sell these things to induce sweating) I sat in there for 15-20 minutes, did a full 100 military style (1,2,3,1 1,2,3,2 etc) jumping jacks, then proceeded to do 30 pushups and 25 sit ups, again military style, in preperation for basic training in Texas. I was fine. Didn't eat or drink for the next two days as I was right at my weight limit, had no problems. So yeah... Mind you that I live in a part of the country were 95 degree temperatures with 97%+ humidity from May to October are completely normal.

Yes, I have witnesses to this.

Serpentine
2009-06-30, 09:02 AM
The rules do mentions minutes, not hours.

I frequently visit the sauna, with temperatures ranging from 80 to 102 Celcius. And yes, 102 is fracking hot, I can't stand it for more than a couple of minutes, but I frequently spend more than half an hour in 95 degrees saunas. No biggie there.

Ofcourse, you're naked and lounging around but still......
So, according to you, the air directly around your body was at the boiling point for water.
...
You're mostly water.
...
Your body should have been boiling.
...

I call shenanigans and/or misinformedness.

Kris Strife
2009-06-30, 09:04 AM
...
So, according to you, the air directly around your body was at the boiling point for water.
...
You're mostly water.
...
Your body should have been boiling.
...

I call shenanigans and/or misinformedness.

Specific heat. It takes time for water to boil, and I believe the human body has a higher specific heat than pure water.

Fan
2009-06-30, 09:04 AM
...
So, according to you, the air directly around your body was at the boiling point for water.
...
You're mostly water.
...
Your body should have been boiling.
...

I call shenanigans and/or misinformedness.

That's why we have SKIN my dear serpentine, and sweat. To cool our internal body temp below the infernal water boiling mark. There's also the thickening agents, and the blood, and tissue in our bodies to prevent such temp's from immediately effecting us. However, his stomach should have been very upset as the water in his stomach got REALLY hot, and started re cooking the pasta he ate last week,

Serpentine
2009-06-30, 09:07 AM
I'm still not hearing the bit where air heated to boiling point is anything but at the very least potentially very harmful...

Fan
2009-06-30, 09:09 AM
I'm still not hearing the bit where air heated to boiling point is anything but at the very least potentially very harmful...

Not arguing that, just saying that he wouldn't be boiling. I do agree that it would be harmful at the very least in the long term, and thats with proper hydration that most people don't get.

Fixer
2009-06-30, 09:10 AM
That's why we have SKIN my dear serpentine, and sweat. To cool our internal body temp below the infernal water boiling mark. There's also the thickening agents, and the blood, and tissue in our bodies to prevent such temp's from immediately effecting us. However, his stomach should have been very upset as the water in his stomach got REALLY hot, and started re cooking the pasta he ate last week,You are ignoring physics.

If your internal body temperature is 98.5 F, and the external temperature is 100 C, there is a movement of energy from the high energy source (the air) to the low energy source (the body). Thus, if you are wet you ABSORB heat faster than if you are dry. This is why hot water scalds faster than hot air at the same temperature.

And, to point out, 98.5 F is about 37C. 100C is almost three times hotter than 37C. The amount of energy being transferred INTO the body, thereby increasing its temperature, would be massive. Adding humidity increases this transfer.

100C = 212 F

When was the last time you encountered human life existing ANYWHERE near 212 F?

Fan
2009-06-30, 09:23 AM
You are ignoring physics.

If your internal body temperature is 98.5 F, and the external temperature is 100 C, there is a movement of energy from the high energy source (the air) to the low energy source (the body). Thus, if you are wet you ABSORB heat faster than if you are dry. This is why hot water scalds faster than hot air at the same temperature.

And, to point out, 98.5 F is about 37C. 100C is almost three times hotter than 37C. The amount of energy being transferred INTO the body, thereby increasing its temperature, would be massive. Adding humidity increases this transfer.

100C = 212 F

When was the last time you encountered human life existing ANYWHERE near 212 F?

Didn't he say 100 Degrees F... If he said C then I do indeed call Shenangins. :smallyuk:

LibraryOgre
2009-06-30, 09:24 AM
Eh, having been in a sauna set to 120 degrees farenheight, wearing what amounted to a pair of black plastic trash bags cut into the shape of pants and a long sleeve shirt (yes, they sell these things to induce sweating) I sat in there for 15-20 minutes, did a full 100 military style (1,2,3,1 1,2,3,2 etc) jumping jacks, then proceeded to do 30 pushups and 25 sit ups, again military style, in preperation for basic training in Texas. I was fine. Didn't eat or drink for the next two days as I was right at my weight limit, had no problems. So yeah... Mind you that I live in a part of the country were 95 degree temperatures with 97%+ humidity from May to October are completely normal.

Yes, I have witnesses to this.

So, in short, you passed your fortitude saves, perhaps due to a high Con or a Great Fortitude feat.

Kris Strife
2009-06-30, 09:27 AM
So, in short, you passed your fortitude saves, perhaps due to a high Con or a Great Fortitude feat.

Except I was overweight, in less than great shape at the time (in terrible shape now. Cursed knee injuries!) and don't like going out in the heat...

Telonius
2009-06-30, 09:28 AM
Well, BooNL is in the Netherlands, so the boiling point might be a fraction of a degree higher (below sea level and all).

Zid
2009-06-30, 09:37 AM
You are ignoring physics.

If your internal body temperature is 98.5 F, and the external temperature is 100 C, there is a movement of energy from the high energy source (the air) to the low energy source (the body). Thus, if you are wet you ABSORB heat faster than if you are dry. This is why hot water scalds faster than hot air at the same temperature.

And, to point out, 98.5 F is about 37C. 100C is almost three times hotter than 37C. The amount of energy being transferred INTO the body, thereby increasing its temperature, would be massive. Adding humidity increases this transfer.

100C = 212 F

When was the last time you encountered human life existing ANYWHERE near 212 F?

Talking about ignoring physics: Measuring tempratures in Farenheit or Celcius!

Kelvin is the only proper way to measure heat!

Sewercop
2009-06-30, 09:42 AM
Just about every person i know has been in a sauna of 90+ celsius.
Track down a finnish guy or gal. They have competitions in sauna sittings.
Heck, track down a nordic person and they will probably tell you the same as i do.

That is in a sauna. If it were 90 degrees celsius outside in the sun you would die fast..
Like really really really fast :)

But i believe that the above 90 degrees fahrenheit rule are stupid.. Guess most of southern Norway would have died the last week if it were true :)

Random832
2009-06-30, 09:47 AM
Probably these people who are talking about 90 100 110 celsius saunas are losing the distinction between a heating element somewhere in the room being at that temperature (which makes some sense) vs the air temperature in the whole room being that hot (which does not make sense)

Signmaker
2009-06-30, 10:02 AM
Don't quite see the problem. Saunas=Relaxation, often in the nude (or close to it).

An adventurer tends to be quite active. Loaded down with gear, not factoring in armor. So yes, things can get quite dangerous.

As to the nordic elements, they obviously are able to Endure the Elements quite well, due to their natural conditioning.

Fixer does a pretty good job of keeping things 'in perspective' with that burn table.

J.Gellert
2009-06-30, 10:05 AM
The heat rules are actually rather lax because they don't account for heatstrokes. In one battle of the American Revolutionary War, more soldiers died from heat than from enemy fire.

Eldariel
2009-06-30, 10:20 AM
Just about every person i know has been in a sauna of 90+ celsius.
Track down a finnish guy or gal. They have competitions in sauna sittings.
Heck, track down a nordic person and they will probably tell you the same as i do.

Dry sauna can go up to 120-140 and still be bearable. With the humidity from the water to the stones though, above 100 gets a bit hot. And those competitions, it's mostly between guys and mostly teens and kids at that. I know I haven't had one since the age of 15.


That is in a sauna. If it were 90 degrees celsius outside in the sun you would die fast..
Like really really really fast :)

Yeah, the important thing to realize here is that in a sauna, the humidity is miniscule. That's why throwing water to the stones causes such a drastic sensation of heat increase, and that's why temperatures twice higher than what's bearable outside are perfectly ok in sauna. Indeed, the Turkish sauna would cause scalding if the temperatures were near what they are in Finnish saunas.

There's a thin layer of air on the skin that acts as insulation from the outside air and temperature. Water breaks this layer (wind works like this too, hence why standing naked in a winter night doesn't feel cool until you feel the breeze), exposing the skin directly to the heat, which causes the vast differences in how much heat a man can tolerate in any given conditions. As D&D does not really model humidity, wind or the like, the heat danger rules make sense just fine as they are only approximations at best due to so many factors being unaccounted for.

Talya
2009-06-30, 10:27 AM
100 degree Celsius air would sear your mouth and lungs with every breath. try sticking your finger in 99 degree C water for even a half second and see what happens.

Hint: to get water to 99 degrees C, put a pot on the stove, wait until it's bubbling violently. (At 100 degrees, it's no longer water, but steam. If you think a gas like air would behave differently than liquid water, try what a steam burn feels like.)

Random832
2009-06-30, 10:28 AM
Dry sauna can go up to 120-140 and still be bearable. With the humidity from the water to the stones though, above 100 gets a bit hot.


If you're talking about celsius temperatures above 100, isn't that the temperature of the stones, not of all the air in the room?

Talya
2009-06-30, 10:28 AM
If you're talking about celsius temperatures above 100, that's almost certainly the temperature of the stones, not of all the air in the room.

That's likely.

ericgrau
2009-06-30, 10:33 AM
A desert or similar that gets above 140 F can, in reality, be fatal. This is a known fact. It's as simple as that. I assume those places have no humidity, so perhaps that's what makes the difference. A desert is not a sauna.

Btw, did I miss something? Is it nitpick week this week?

Indon
2009-06-30, 10:33 AM
I think, based on the Wikipedia article (http://en.wikipedia.org/wiki/Sauna), that we can conclude that saunas are not representative of the effect of heat on human beings, and are probably explicitly designed to be extremely hot conditions with mitigating factors that allow humans to survive in them - as air at 200 degrees F would certainly prove fatal in a matter of minutes in other conditions, as the heat transferrence into your body through your lungs would be extremely high.

I think, other than the housecat-commoner problem (normal people aren't given enough HP) and the fact that extreme heat doesn't get a saving throw, the heat system works just fine.

Myrmex
2009-06-30, 11:27 AM
Specific heat. It takes time for water to boil, and I believe the human body has a higher specific heat than pure water.

No; our body has a higher specific heat than water vapor. Pure water has a higher specific heat than our body.

Worira
2009-06-30, 12:09 PM
So, in short, you passed your fortitude saves, perhaps due to a high Con or a Great Fortitude feat.

You don't get saves when the temperature is above 60 degrees.

Renegade Paladin
2009-06-30, 12:24 PM
This is ridiculous. I was out last weekend fencing with my SCA group. We were at a major event, lots of people fighting. The ambient temperature averaged 97F at about 98% humidity. The armored combat was called off at 10:30. Why? It was so hot that people were already starting to suffer from heat exhaustion, and that's with long breaks between every scenario and a dedicated crew of people running water and sports drinks to everyone involved. We fencers, being crazy (and possessed of a field with shade trees, rather than the bare one the heavies had), kept going until the afternoon, when one of our number briefly collapsed due to the heat. Apparently, strenuous activity in temperatures above 90F is dangerous. Who knew? :smallsigh:

Using saunas to try and model heat dangers is the real joke here.

Fixer
2009-06-30, 12:33 PM
I pulled this from the Sauna wikipedia article.
Under many circumstances, temperatures approaching and exceeding 100 °C (212 °F) would be completely intolerable. Saunas overcome this problem by controlling the humidity. The hottest Finnish saunas have relatively low humidity levels in which steam is generated by pouring water on the hot stones. This allows air temperatures that could boil water to be tolerated and even enjoyed for longer periods of time. Steam baths, such as the hammam, where the humidity approaches 100%, will be set to a much lower temperature of around 40 °C (104 °F) to compensate. The "wet heat" would cause scalding if the temperature were set much higher.So, the issue here is that saunas are EXTREMELY controlled conditions. In these controlled conditions, a human can endure a higher-than-normal heat condition for a longer-than-normal time. This is due to the heat being unable to easily enter our bodies due to lack of humidity (and likely reduced respiration volume).

However, it should be noted that most adventurers do not exist in controlled conditions, and a volcano's interior does not qualify as controlled.

ashmanonar
2009-06-30, 12:56 PM
Alright, I tested it.

Me and my buddy went to 90 Celcius Sauna and throwed a small ball for an hour, while wearing t-shirts, jeans etc... and Cookwares on our heads.

It made me thirsty, but nothing lethal.

Pics or it didn't happen.

The New Bruceski
2009-06-30, 01:12 PM
Also consider that it's 1d4 damage, which is quite a range when it starts adding up. I played volleyball in 80-degree weather, tried to stay hydrated, and biked home, then found I was suffering from heat exhaustion. Others more out-of-shape than I was had no problems. I rolled higher on my nonlethal damage.

Ravens_cry
2009-06-30, 01:26 PM
200 f degree steam is far more leathal then the equivalent dry air for two reasons. One, steam is a much better conductor of heat then dry air. Which means the excess heat can get into you faster.
Two, all that moisture in the air means it is basically saturated, so little or no water from sweat can evaporate and in so doing cool you off. So it your bodies cooling system is nullified. Humans can stand dry heat quite well, with plenty of water, compared to moist heat.
Stick your hand in the oven when it's on, and even though the air may be 350 f degrees, way above the boiling point of water, it's not a good conductor. Just don't touch the racks or even whatever is roasting in there as they conduct heat oh so much better and will burn or scald you good.

Indon
2009-06-30, 01:31 PM
200 f degree sauna is far more leathal then the equivalent dry air for two reasons. One, steam is a much better conductor of heat then dry air. Which means the excess heat can get into you faster.
Two, all that moisture in the air means it is basically saturated, so little or no water from sweat can evaporate and in so doing cool you off. So it your bodies cooling system is nullified. Humans can stand dry heat quite well, with plenty of water, compared to moist heat.
Stick your hand in the oven when it's on, and even though the air may be 350 f degrees, way above the boiling point of water, it's not a good conductor. Just don't touch the racks or even whatever is roasting in there as they conduct heat oh so much better and will burn or scald you good.

Did you read the part where everything wikipedia said was basically the opposite of what you're saying here?

Renegade Paladin
2009-06-30, 01:39 PM
Did you read the part where everything wikipedia said was basically the opposite of what you're saying here?
Consider that Wikipedia is highly unreliable. :smalltongue: It's right in this case, but only until some yahoo decides to sabotage it.

The problem is not that Ravens didn't read Wikipedia; it's that she apparently doesn't understand how a sauna works. Remove references to a sauna and she's right; humid heat is comparatively more deadly. The problem is that she is conflating a sauna with a steam bath, which is understandable since in the American usage, the terms are often interchanged.

Random832
2009-06-30, 01:53 PM
Consider that Wikipedia is highly unreliable. :smalltongue: It's right in this case, but only until some yahoo decides to sabotage it.

The problem is not that Ravens didn't read Wikipedia; it's that she apparently doesn't understand how a sauna works. Remove references to a sauna and she's right; humid heat is comparatively more deadly. The problem is that she is conflating a sauna with a steam bath, which is understandable since in the American usage, the terms are often interchanged.

She's not the only one - an earlier post in this thread claimed that a sauna is actually safer _because_ of the alleged humidity (i.e. water vapor somehow conducts heat away from the body into the [hotter] air, in clear violation of the second law of thermodynamics)

Riffington
2009-06-30, 01:57 PM
All you sauna-fanciers: go ahead and bring a small glass of water into the sauna. Put a thermometer in the water, and hold the glass in your hand. Go ahead and tell us how high the thermometer in your glass gets before you have to drop the glass or leave...

TSED
2009-06-30, 02:00 PM
Pure anecdotal evidence: I am a total wuss when it comes to heat. When it starts getting about 25C I can definitely feel (and suffer) the fact.

I simply cannot imagine living in a southern clime. Urghhhh.

Eldariel
2009-06-30, 02:02 PM
If you're talking about celsius temperatures above 100, isn't that the temperature of the stones, not of all the air in the room?

No, it's the air temperature (how the hell would you go about measuring the temperature of the stones, anyways?). As I mentioned, it's a dry sauna, or a sauna with little to no humidity effectively removing the conduit.

The hottest sauna I've ever been in is 110 degrees celcius (yes, it was a dry sauna), with the usual temperatures being 80-100 degrees celcius for standard Finnish sauna.


All you sauna-fanciers: go ahead and bring a small glass of water into the sauna. Put a thermometer in the water, and hold the glass in your hand. Go ahead and tell us how high the thermometer in your glass gets before you have to drop the glass or leave...

How big a glass exactly? Desilitre? Two? That obviously determines how long it takes for the water to warm up. Because I just might next Friday.

Vandin
2009-06-30, 02:03 PM
For a random first hand experience, I spent 2 years living in Riyadh, Saudi Arabia, where the temp was practically never under 110F in the shade. The city essentially shuts down (and/or stays indoors) during midday, because it's just too hot to be doing anything that can wait.

We once took a trip to a river a few miles outside the city, and while I don't remember the exact temp, I know it was tolerable until we hit the river, at which point the humidity+temp just about had us passing out inside of 15 minutes doing nothing beyond simply walking around.

Sauna: it's..uh, nothing like the real thing.

Eldariel
2009-06-30, 02:05 PM
Sauna: it's..uh, nothing like the real thing.

This. Let's keep the sauna-discussion separate from what a man can normally survive in; the conditions in sauna are very different from those we normally encounter outdoors.

I have to confess that I got a sunstroke during a one-week stay in Greece when it was 40 degrees Celcius in the shade (because I didn't drink enough, duh; it involved a two-hour drive with nothing to drink).

Riffington
2009-06-30, 02:24 PM
How big a glass exactly? Desilitre? Two? That obviously determines how long it takes for the water to warm up. Because I just might next Friday.

Sure, try it with a two deciliter (6-7 oz) glass. I would guess that the difference between the two sizes would only be a couple of degrees or so however, so it might not matter. But I'd be curious how high it gets for you.

Fixer
2009-06-30, 02:25 PM
Yeah, in the US we have saunas, but they involve hot rooms with lots of humidity all over the place, and they don't go to 100C without someone dying. If your saunas in other countries are completely dry, I can understand being able to tolerate them at higher temperatures. Where I am, in Florida, with 100% humidity, 99% of people can barely tolerate moving in 100F for 15 minutes without health issues.

I have provided what I can to explain the D&D rules aren't unreasonable for the average person. If an individual can survive these sorts of things for prolonged periods with little to no effect they either have the Endurance and/or Heat Endurance feats.

Ellye
2009-06-30, 02:26 PM
I live in a place where we sometimes hit the 45C mark. People get ill. Like, really ill - could very well be fatal in a long term exposure.
And that's 15C below the 60C mark.

Ravens_cry
2009-06-30, 02:26 PM
I did something stupider, I took a 36 hour bus ride, thankfully mostly at night, with nothing to drink. The bus stopped at this one bus stop 5/8ths of the way there and I bought a bottle of water. I don't think I drank it so much as absorbed it, it just sucked in. If I ever take that trip again, I am taking bottles of water.

hamishspence
2009-06-30, 02:30 PM
According to the Guinness Book of Records I have (admittedly an older copy,) you generally do not get air temperatures above 140F in the shade- and even that is rare- hottest of hot deserts.

In this- severe heat (just below 140F), without protection, you take 1d4 non-lethal damage every 10 min if you fail your save.

That does seem plausible.

MickJay
2009-06-30, 02:50 PM
Quick trip to the wiki: "The Finnish-style sauna (generally 70–80 °C (158–176 °F)), but can vary from 60 to 120 °C (140–248 °F) and the wet steam bath are the most widely known forms of sweat bathing." http://en.wikipedia.org/wiki/Sauna#Similar_sweat_bathing_facilities

Eldariel
2009-06-30, 02:51 PM
Yeah, in the US we have saunas, but they involve hot rooms with lots of humidity all over the place, and they don't go to 100C without someone dying. If your saunas in other countries are completely dry, I can understand being able to tolerate them at higher temperatures. Where I am, in Florida, with 100% humidity, 99% of people can barely tolerate moving in 100F for 15 minutes without health issues.

Yeah, those are steam rooms to us; Finns call them "Turkish sauna" (they feel damn cool, but at the same time one is aware that if it were any hotter there, you'd get burned). My experiences are mostly limited to Finnish sauna, of course (sure, I've been to steam baths in different facilities numerous times, but I've pretty much used Finnish sauna daily for the whole of my life save for infancy and few trips). The same ones MMA fighters and boxers use for weight loss, for example.

Fixer
2009-06-30, 02:53 PM
With all that conditioning it is not surprising to believe you have Heat Endurance as a feat.

hamishspence
2009-06-30, 02:59 PM
Problem is that Heat endurance alone is no help in temperatures past 140F- protective clothing is needed. and at 140F the feat causes you to make checks every hour instead of every 10 minutes.

I'm guessing its simply that Saunas Are Different- 248F true air temperature- way past boiling water- wouldn't that cause one to expire rapidly?

Eldariel
2009-06-30, 03:04 PM
I'm guessing its simply that Saunas Are Different- 248F true air temperature- way past boiling water- wouldn't that cause one to expire rapidly?

As I explained before, it's a matter of humidity, or rather a lack thereof.

hamishspence
2009-06-30, 03:09 PM
But how humid are, say, Death Valley, or that place in Lybia where it was recorded? I thought hot sandy/rocky deserts are very low humidity.

Is it that which makes saunas so much less taxing, or are dry deserts more humid than I guess?

only1doug
2009-06-30, 03:17 PM
But how humid are, say, Death Valley, or that place in Lybia where it was recorded? I thought hot sandy/rocky deserts are very low humidity.

Is it that which makes saunas so much less taxing, or are dry deserts more humid than I guess?

I've been to death Valley (when I visited the states years ago), Walking out of the Airconditioned RV into the desert was very much like stepping into a sauna (dry type) it was hot and arid, you could take it for a few minutes but it would become lethal if you stayed there too long. It's easy to leave a sauna when you've had enough, and commercial sauna's are regularly checked to ensure that the occupants are OK. It's much more difficult to get out of a desert when you feel that the heat is getting too much.

Eldariel
2009-06-30, 03:17 PM
But how humid are, say, Death Valley, or that place in Lybia where it was recorded? I thought hot sandy/rocky deserts are very low humidity.

Is it that which makes saunas so much less taxing, or are dry deserts more humid than I guess?

*shrug* That's an excellent question; why don't the same rules that apply to sauna apply there? My own uneducated answer would be that a brief visit to said deserts is no more dangerous than a brief visit to a sauna. The big differences I can decipher are the existence of the sun there (sunlight, as we all know, is the real source of heat on the planet and the fact that you're under the direct sunlight there means that the heat is directly transmitted from the light to you; that would be akin to sitting on the stove in sauna, and explains the need for clothes for insulation and why the lower air temperature isn't telling the whole story) and the fact that you spend only ~15-30 mins max at a time in sauna, while your unfortunate visit to the desert is unlike to be as brief. Ultimately, I'd wager sun is the biggest difference-maker with deserts (as I understand, the lack of humidity specifically serves to make the sunlight more intense).

Heliomance
2009-06-30, 03:24 PM
At a guess (I could be completely wrong) I'd say that the primary method of heat transfer in a sauna is likely convection, whereas in a desert the primary method is radiation, which is a far more efficient process. I suspect this is why sauna temperatures are bearable higher than in real life.

Eorran
2009-06-30, 03:27 PM
The thing is, exposure to a (dry) sauna is typically on the order of minutes. I'm sure that endurance competitions may last hours, but that's done by people who have conditioned themselves to the exposure. Additionally, sauna exposure is typically done nude or nearly nude, with little exertion, and sauna-goers know the importance of hydration before & after. Plus, no sun - direct sulight exposure can cause burns, and can shut down your cooling system(sweating).

Another thought - saunas have little to no air movement, which allows your body to create an insulting layer of air right near your skin. With a breeze, though you'd feel cooler, you would end up losing more water, and probably heating up faster. This is just a theory, though.

Temperatures above about 150F / 65C cause bacteria to die. A few degrees beyond that and protein chains start to break down (ex. eggs turning from liquid to solid). Unless you are able to keep your body temp lower than that, you will die.

Yeah, a steam or wet sauna at 70C would kill you horribly in a matter of minutes.

Eldariel
2009-06-30, 03:34 PM
Another thought - saunas have little to no air movement, which allows your body to create an insulting layer of air right near your skin. With a breeze, though you'd feel cooler, you would end up losing more water, and probably heating up faster. This is just a theory, though.

Just for an idea of how big a factor this is, with a strong wind, -5 degrees Celcius can be lethal to a naked man, while the same number is -40 degrees for still air.

hamishspence
2009-06-30, 03:42 PM
I thought that temperatures much higher than that were lethal to a guy with no shelter, overnight- exposure sets in easy.

Winter exposure and no clothing- maybe as high as 5 celsius will end with a badly hypothermic victim.

Eldariel
2009-06-30, 03:47 PM
I thought that temperatures much higher than that were lethal to a guy with no shelter, overnight- exposure sets in easy.

Winter exposure and no clothing- maybe as high as 5 celsius will end with a badly hypothermic victim.

Those numbers are for a short-term exposure. Wish I could remember exactly how long; the reason I posted them was the comparative impact of the wind though.

hamishspence
2009-06-30, 03:48 PM
Wind Chill Factor's pretty well known- I hadn't thought about the possibility of there being a Wind Heating Factor though.

Random832
2009-06-30, 04:04 PM
Wind Chill Factor's pretty well known- I hadn't thought about the possibility of there being a Wind Heating Factor though.

Most weather temperatures in temperate climates - even 95 F (35 C) are below body temperature, so wind usually makes it feel cooler.

only1doug
2009-06-30, 04:05 PM
Wind Chill Factor's pretty well known- I hadn't thought about the possibility of there being a Wind Heating Factor though.

Ever used a Fan assisted oven? Typical cooking instructions state "if using fan assisted oven reduce temperatures by 10 Degrees (C)" thats with what is effectively a very gentle breeze.

AslanCross
2009-06-30, 04:31 PM
After reading the wiki article, I stand corrected: it's the relative lack of humidity in a sauna that allows it to be more tolerable. (High-humidity steam baths actually have way lower temperatures.)

Seriously, though. I live in a tropical country. Humidity and heat are routinely very high. We have two seasons: "hot" and "hot with rain." The temperature does drop to comfortable levels around December and January, but the average weather during this time is like this:
1. The sun rises. It's a clear day. The temperature increases to about 35-37 C at around lunch time.
2. Cloud cover increases, trapping the heat.
3. It rains, very hard, for about half an hour. There is no wind, just driving rain.
4. The rain stops, but the cloud cover stays.

Such weather feels positively miserable, even to someone like me who's lived here all my life. Throw in poorly-ventilated indoor conditions that were not explicitly designed for comfort (like the government school I teach in, or a dungeon or cave), and it gets quickly uncomfortable. That's at 35 C, which is even lower than body temperature. Adventurers in an active lava tube are going to be exposed to temperatures way higher than that. Plus dry heat and toxic gas.

Myrmex
2009-06-30, 09:20 PM
Did you read the part where everything wikipedia said was basically the opposite of what you're saying here?

Actually, hot steam will burn you really badly, since it has a higher specific heat than dry air. This is especially true if the steam is moving, since it will move heat into your body.

If you don't believe me, next time you're boiling noodles, stick your hand right over the top with a thermometer. I bet you won't be able to hold the thermometer there long enough to get an accurate reading. :smallbiggrin:

Renegade Paladin
2009-06-30, 11:28 PM
Temperatures above about 150F / 65C cause bacteria to die. A few degrees beyond that and protein chains start to break down (ex. eggs turning from liquid to solid). Unless you are able to keep your body temp lower than that, you will die.
You will die long before that; organ failure from high core temperature sets in far below the temperature needed to break down protein chains.

VirOath
2009-07-01, 12:29 AM
Okay, people need a verse in physics. It must be done. FOR SCIENCE! (And yes, I do mean for some of the people at the start of this convo...)

*Coughs* Ahem, okay, got that out of my system.

First off is the basic transference of energy. This is a factor of how much energy is required to change it's temperature by one degree. In the end this is based mostly off of Density.

Density, melting point and boiling point derive how much energy (Or heat) a substance can hold in one form. The less energy it can hold the more energy is lost when transferring that energy from one point to another (Example, the air is bad at holding heat, changing temperature very quickly when the source is removed. You can observe this by going into the shade on a sunny day. Water and Metals are better at holding heat, as you will find heating elements and boiling water to still be hot for quite a while after being removed from the source of that heat.)

The Sauna Factor, steam rooms are good:
Now, you have the heat of the Element (the Sauna Heater), the heat of the water, the heat of the steam, and you. For the sake of making this simple, we will ignore the benches and such you would sit on.

Heat from the Element is transferred to the water, that water turns to steam and EXPANDS (This is the key point that most people are missing!), reducing the total energy as it turns from water to steam, yet remaining about the same temperature.

This steam/air moves away from it's heat source and encounters you (Again, to keep this simple we will assume that the entire room is the same temperature so energy is not lost in transference from the water to you, and ignoring time, which would also lose energy).

Now, it should be clear that you have a higher density than the steam, as well as a higher mass and surface area than the water you poured onto the element. This means that Less energy is being spread over a Higher surface area to affect a Greater density and mass.

Hence why steam will not boil you inside and out in seconds in a Sauna. Your body absorbs the energy in the air, turning the steam back to water on your skin, which Energy Transference will make sure that some heat is left in and it will fall off your body onto the floor. This is how sweating works, and how the body regulates it's own temperature. It will require a mountain of energy compared to what the air holds to be a danger.

This is why you can sit inside a Sauna on a comfortable temperature for a long time. But this becomes more extreme as the temperature raises, as it means the air holds more, and having a high surface area vs volume means that there is more area for the heat to cover, making this dangerous. Dry Sauna's take advantage of this, cramming 30 minutes exposure into a short 3.

Boiling points and You:

Now you might be wondering how sweat can evaporate yet not burn you. This is more than one factor. First is that liquids can evaporate before reaching their boiling point. Boiling point is the temperature that it cannot pass(Well, it can. Extra heat can be held pass this tolerance, but it will bleed off insanely fast), so the liquid rapidly turns into vapor compared to at lower temperatures, as the excess heat/energy pushes more of it's mass to turn. You can observe this by putting a glass of water out on a hot summer day and leaving it. After a few hours that glass will be lower than when you filled it.

After all, water from our lakes and rivers evaporate under the sun to form clouds all the time, yet our lakes aren't boiling now, are they?

The Desert, dessert for the dead:
Now when you make the air temperature too hot to hold water well (Again, hot air is less dense, holds less water per cubic foot), you remove the buffer that condensation gives in the Sauna. Add to it that you generally are under a direct source of energy (The SUN) which is providing heat instead of getting it through a medium (Steam in the Sauna), with little protection from the thin air. You cover or you burn. Burnt skin doesn't sweat and traps heat like leather. You need to constantly provide water to the system (this is an act of cooling in itself, since your body is transferring heat to the cooler water) and stay out of direct sun light.

There is a world of difference between the two. Even still, Sauna's are still dangerous, they still do cook you, just at a much slower rate.

Juggernaut1981
2009-07-01, 12:34 AM
Okay... some basic physics and chemistry...

Mixed Liquids/Dissolved Solids
Water + (something other than water) will in general reduce the specific heat of the liquid. That's why people put salt in water to boil vegetables, it reduces the boiling point of water.

Heat Transfer
When you make "surfaces" you consume energy. That's how evaporative cooling works. You first put water into something (say cloth) and as you blow air through it you make surfaces and those surfaces suck energy from everything nearby. So in a not-very humid sauna you will have water land on your body, then some energy exchanges will happen and the net result will be you losing a small amount of energy to the water drop as it leaves. Also, anything that has more ways to "use energy" (surfaces, ways of rotating, shape deforming, etc) has more ways of creating entropy and thereby obeying the laws of Thermodynamics in general (the NET entropy of the system increases).

What heat causes problems
I've lived in regional Australia. We frequently have very hot dry conditions in summer. Some towns I have lived in have regular daily temperatures of 35+C and <10% humidity. People get heatstroke very frequently. When I was teaching students suffered the most heatstroke at swimming carnivals when you would think they would be "fine" because of the water in the pool. And so on and so on. There is very little you want to actually do in Summer in 35+C heat in the sun... you mostly want to find somewhere that has any kind of breeze, is in the shade and preferably has some water to put on yourself.

So from personal experience, I'd say that the heatstroke rules sound perfectly appropriate for people trying to travel a 4-6km/h walking in 10+kg of metal plus other miscellaneous equipment.

quick_comment
2009-07-01, 12:51 AM
Okay... some basic physics and chemistry...

Mixed Liquids/Dissolved Solids
Water + (something other than water) will in general reduce the specific heat of the liquid. That's why people put salt in water to boil vegetables, it reduces the boiling point of water.

Specific heat != boiling point.



Heat Transfer
When you make "surfaces" you consume energy. That's how evaporative cooling works. You first put water into something (say cloth) and as you blow air through it you make surfaces and those surfaces suck energy from everything nearby. So in a not-very humid sauna you will have water land on your body, then some energy exchanges will happen and the net result will be you losing a small amount of energy to the water drop as it leaves. Also, anything that has more ways to "use energy" (surfaces, ways of rotating, shape deforming, etc) has more ways of creating entropy and thereby obeying the laws of Thermodynamics in general (the NET entropy of the system increases).

:smalleek:

When water condenses it releases energy, when it evaporates it absorbs energy. No need to start talking about entropy here.

Grady
2009-07-01, 01:13 AM
As a person living in rural Australia I can safely say that heat danger is very real.

There was a heat wave earlier this year where the hottest day got to 48C where I live. That's 118F. The average UK heat wave, by comparison, is roughly 37C, or 98.6F.

The average summer's day where I live is anywhere between 35C and 45C, enough to be considered "heat wave" conditions in many areas of the world.

These are temperatures where you can barely walk for a straight twenty minutes without feeling exhausted, let alone march for eight hours straight in full plate armor, or fight for your life reliably.

Living in and doing day-to-day activities in this weather leads me to believe that, yes, it is extremely possible to be exhausted and knocked out by such heat, and while i'm no expert i'd say 60C has the potential to be fatal with direct exposure while doing strenuous activity for a number of minutes (remembering 60C is over half way to boiling point).

Gaiyamato
2009-07-01, 02:36 AM
There is this thing called "Steadman Apparent Temperature" which is a measure of the real temperature after humidity, wind chill and even clothing is taken into account.
It is nearly always lower than the actual temp.

In a sauna the AT is actually more than halved from the measured temp.
Outdoors, unless you have a nice cool breeze or some shade it can often be almost equal to the real temp.
If you are performing strenuous activity and/or wearing innaproriate clothing you can add as much as 8C to the AT which can easily push it above the real temperature.

This AT is the measurement of the true effect on our bodies. It explains why massive temperatures can be almost enjoyed in a sauna yet are totally lethal in a desert environment.

That said people have died in saunas quite a bit over the history of saunas, so they hardly safe.

If anything the D&D 3.5 rules are in fact a bit soft. lol.

only1doug
2009-07-01, 02:30 PM
Okay, people need a verse in physics. It must be done. FOR SCIENCE! (And yes, I do mean for some of the people at the start of this convo...)
<snip>
Now when you make the air temperature too hot to hold water well (Again, hot air is less dense, holds less water per cubic foot.

Please remember that you asked for the physics lesson :P

the Higher the air temperature the better it is at holding water. Hot air can hold much more water than cold air. When air is cooled enough it will reach the point that it cannot hold all the water anymore and some of the water will drop out of the air. (those of us in england are very familiar with this process, we call it rain). (In england it often rains in summer, this year its been raining indoors where I work - see spoiler for details)

with the unusual High Humidity with have noticed a flaw with the buildings Airconditioning design, specifically it has no dehumidification design on its Main Air Handling units and the chilled ceiling design results in condensation forming and the dripping down within the office.


Relative Humidity is the measure of how much water the air is capable of holding at its current temperature, it is a percentage with 0% being completely dry and 100% being completely saturated.

Wikipedia has a psychrometric chart (http://en.wikipedia.org/wiki/File:PsychrometricChart-SeaLevel-SI.jpg) which could be used to calculate the specific water content of air at a given temperature, pressure and humidity. It's complicated stuff though, I don't use it regularly enough to talk in detail without re-reading it.

Learnedguy
2009-07-01, 02:43 PM
Having done quite a bit of job outside in the sun, I have to say, those heat dangers aren't anything to scoff about. Sure, you might be able to sit in a sauna at that temperature, but actually doing some work?

Not a chance. You'll burn out in minutes, overexerting yourself.

Worira
2009-07-01, 02:46 PM
The Sauna Factor, steam rooms are good:
Now, you have the heat of the Element (the Sauna Heater), the heat of the water, the heat of the steam, and you. For the sake of making this simple, we will ignore the benches and such you would sit on.

Heat from the Element is transferred to the water, that water turns to steam and EXPANDS (This is the key point that most people are missing!), reducing the total energy as it turns from water to steam, yet remaining about the same temperature.

This steam/air moves away from it's heat source and encounters you (Again, to keep this simple we will assume that the entire room is the same temperature so energy is not lost in transference from the water to you, and ignoring time, which would also lose energy).

Now, it should be clear that you have a higher density than the steam, as well as a higher mass and surface area than the water you poured onto the element. This means that Less energy is being spread over a Higher surface area to affect a Greater density and mass.

Hence why steam will not boil you inside and out in seconds in a Sauna. Your body absorbs the energy in the air, turning the steam back to water on your skin, which Energy Transference will make sure that some heat is left in and it will fall off your body onto the floor. This is how sweating works, and how the body regulates it's own temperature. It will require a mountain of energy compared to what the air holds to be a danger.

This is why you can sit inside a Sauna on a comfortable temperature for a long time. But this becomes more extreme as the temperature raises, as it means the air holds more, and having a high surface area vs volume means that there is more area for the heat to cover, making this dangerous. Dry Sauna's take advantage of this, cramming 30 minutes exposure into a short 3.


Umm, no? If steam condenses on your body, it has transferred heat to you, increasing your thermal energy. A steam bath will heat you much faster than a dry sauna.

Froogleyboy
2009-07-01, 03:17 PM
Not sure if its been said but . . . I live in alabama and it gets 115 all the time down here. I don't mind the heat one bit
-R

lsfreak
2009-07-01, 04:24 PM
Not sure if its been said but . . . I live in alabama and it gets 115 all the time down here. I don't mind the heat one bit
-R

You don't mind the heat, okay. But can you walk several miles in the heat at a decent pace (3-4 mph)? How about with 80 pounds of gear? Now throw in a guy with a knife chasing you.

Froogleyboy
2009-07-01, 04:50 PM
I cannot even carry 80 pounds of gear (neither can my character)

But yes, I can walk several miles (7.5 at last count)
-R

hamishspence
2009-07-01, 04:58 PM
Now think about what a Str 10 Con 10 Adventurer can do- walk for 8 hours with a Light Load, day in, day out. Run quite fast with light load for a reasonable amount of time. Hustle with light load for an hour.

Then look at what they can do with corresponding Heavy Load.

D&D adventurers (even at 1st level) are exceptionally fit compared to most real-life people.

Maelstrom
2009-07-01, 05:20 PM
Okay... some basic physics and chemistry...

Mixed Liquids/Dissolved Solids
Water + (something other than water) will in general reduce the specific heat of the liquid. That's why people put salt in water to boil vegetables, it reduces the boiling point of water.



Back to school for you...

Adding Salt to fresh water raises the boiling point to approx 102 C...

Eldariel
2009-07-01, 05:25 PM
Now think about what a Str 10 Con 10 Adventurer can do- walk for 8 hours with a Light Load, day in, day out. Run quite fast with light load for a reasonable amount of time. Hustle with light load for an hour.

Then look at what they can do with corresponding Heavy Load.

D&D adventurers (even at 1st level) are exceptionally fit compared to most real-life people.

It's pretty much in line with my military experiences; a person enduring the kind of physical stress adventuring bestows should be capable of such feats.

"Every" (of course there are lots of people relieved from service due to psychological or physiological conditions, refusal of service [in other words, 6 months of jail] or civil service) Finnish male serves in the military and you are expected to be capable of marching at 6 km/h (~3.7mph) carrying 40kg (~88lb) battle gear pretty much day-in day-out (save for short pauses).

D&D seems to be pretty much in line with this, if you assume soldiers are always hustling. Although the time you can walk seem to be underestimated a tad. While D&D characters may seem more fit than most real life people, that's because D&D characters live in world where physical activity is more constant and pretty much nobody is out-of-shape, really. This is especially true for adventurers. So they're really only working on a level half a year of physical activity can bestow anyone.

Froogleyboy
2009-07-01, 05:28 PM
Now think about what a Str 10 Con 10 Adventurer can do- walk for 8 hours with a Light Load, day in, day out. Run quite fast with light load for a reasonable amount of time. Hustle with light load for an hour.

Then look at what they can do with corresponding Heavy Load.

D&D adventurers (even at 1st level) are exceptionally fit compared to most real-life people.

Unless there my character. I have a 6 in strength and a 4 in constitution

hamishspence
2009-07-02, 11:50 AM
and you'd still be able to:

Walk 24 miles in 8 hours, carrying 20 pounds, not counting clothes, for days on end.
Walk 16 miles in 8 hours, carrying 60 pounds, not counting clothes, for days on end.

Hustle 6 miles in 1 hour with 20 pound load- be undamaged.
Hustle 4 miles in 1 hour with 60 pound load- be undamaged.

Run at a speed of 12 miles per hour, for up to 24 seconds, with 20 pounds, before you start to get winded.
Run at a speed of 8 miles per hour, for up to 24 seconds, with 40 pounds, before you start to get winded.
Run at a speed of 6 miles per hour, for up to 24 seconds, with 60 pounds, before you start to get winded.

Lift 60 pounds over your head.
Lift 120 pounds off the ground and stagger around with it.

Suddenly Str 6 Con 4 doesn't look so shabby.

John Campbell
2009-07-02, 01:38 PM
This is ridiculous. I was out last weekend fencing with my SCA group. We were at a major event, lots of people fighting. The ambient temperature averaged 97F at about 98% humidity. The armored combat was called off at 10:30. Why? It was so hot that people were already starting to suffer from heat exhaustion, and that's with long breaks between every scenario and a dedicated crew of people running water and sports drinks to everyone involved. We fencers, being crazy (and possessed of a field with shade trees, rather than the bare one the heavies had), kept going until the afternoon, when one of our number briefly collapsed due to the heat. Apparently, strenuous activity in temperatures above 90F is dangerous. Who knew? :smallsigh:

Using saunas to try and model heat dangers is the real joke here.

Truth.

I'm an SCA heavy fighter; I actually do this stuff, not just sit in a sauna and imagine I know what it's like. I've lived, and fought, in places like North Carolina, where 90°F with humidity to match is not out of the ordinary for half the year. (And if the temperature's as high as 110°F, or even 100°F? I just Don't Fight. I'm not that stupid. Nothing in the SCA is worth putting the armor on for in that kind of heat. Not like the Middies are really going to overrun our lands and burn our women, steal our homes, and rape our sheep if I don't get out there and kill 'em.)

I can assure you, when you're out there wearing fifty pounds of armor and other gear, including leather or steel plate that doesn't breathe at all and what amounts to a thick blanket underneath for padding, with a heavy steel bucket on your head, and fighting in hand-to-hand combat, which is strenuous in ways that very few other things that humans do are, non-lethal damage is entirely appropriate. Heatstroke happens - and it's life-threatening. Despite our best efforts at keeping people cooled and hydrated, because we don't want to have real casualties, people get medevacced from our big summer wars because of it.

The D&D rules, if anything, are too lax about it. I mean, you can only take 1d4 nonlethal an hour between 90°F and 110°F, even if you're out there fighting in your black-enameled full plate in the blazing sun. Armor ought to increase the frequency of the checks as well as the DC, and if you're actually fighting, the frequency should increase still further, down into a range measured in rounds. The effects ought to go past fatigued into exhausted, too (maybe it does; the rules aren't entirely clear).

Epinephrine
2009-07-02, 02:16 PM
...
So, according to you, the air directly around your body was at the boiling point for water.
...
You're mostly water.
...
Your body should have been boiling.
...

I call shenanigans and/or misinformedness.

No, that's the way a sauna works. A sauna can easily be 90+ degrees C.

The specific heat of air is quite low, especially compared to water. We're mostly water. Water takes a lot more energy to heat up. And there's a lot more of it. All the air in the sauna with you weighs very little, while you weigh a lot - so even 100 degree air can't do much harm to you in the short term, as it simply can't heat you up fast enough. Now, start blowing the air around and you can cook fast. Heck, under my nose can get painful just with the air movement from exhaling.

Eldariel
2009-07-02, 02:34 PM
Sure, try it with a two deciliter (6-7 oz) glass. I would guess that the difference between the two sizes would only be a couple of degrees or so however, so it might not matter. But I'd be curious how high it gets for you.

Now I just gotta hope I last longer than the glass; otherwise it'll be all kinds of embarrassing. I'll get back to you tomorrow (or the day after).

only1doug
2009-07-05, 11:53 AM
Now I just gotta hope I last longer than the glass; otherwise it'll be all kinds of embarrassing. I'll get back to you tomorrow (or the day after).

are you too embarrassed to update?

(I'm getting curious)

woodenbandman
2009-07-05, 12:00 PM
I am in Iraq right now, I am a combat medic.

Thread was over at this point. You don't argue with a trained medical professional, particularly not one who can kick your ass.

Eldariel
2009-07-05, 12:09 PM
are you too embarrassed to update?

(I'm getting curious)

Actually, a surprising turn of events passed this particular test on; I did go to sauna on friday, but at my friend's, not home so I didn't really have the opportunity to do this. I'm going to sauna once or twice over the next week and probably at least once home so I should get it done soon.

only1doug
2009-07-05, 12:56 PM
Thread was over at this point. You don't argue with a trained medical professional, particularly not one who can kick your ass.

I think 90% of the posters since have agreed with him (mainly because he was right), regardless someones ability (or lack thereof) "to kick my ass" makes no difference to whether I debate an issue with them or not.

The thread since that post has remained interesting to me, thus I will continue to follow (and post) until the thread is buried by lack of replies or locked (due to flames or at original posters request)

Edit: (I like discussing science)

hamishspence
2009-07-05, 01:33 PM
Cold dangers (which are lack of heat, so heat-related :smallamused:) seem to be a bit lacking in detail at the colder end. There is a wide range between start of "Unearthly cold" (-51F) and the minimum recorded temperature in Antarctica.

Signmaker
2009-07-05, 03:30 PM
Cold dangers (which are lack of heat, so heat-related :smallamused:) seem to be a bit lacking in detail at the colder end. There is a wide range between start of "Unearthly cold" (-51F) and the minimum recorded temperature in Antarctica.

Frostburn supplement fixes that.

Mitth'raw'nuruo
2009-07-05, 05:34 PM
Thread was over at this point. You don't argue with a trained medical professional, particularly not one who can kick your ass.

eh, just because I run around everyday loaded down like a pack mule, does not make me a master at unarmed combat. I suspect that several members of this forum (not just John Campbell or Renegade Paladin) could thump me rather soundly. That is part of why I carry a M4 and a M9. I'll be darned if I'll be defenses just because I rolled a 1 on my attack roll.


I knew sooner or later some other people with real world experince would post: (Grady).
As a person living in rural Australia I can safely say that heat danger is very real.

There was a heat wave earlier this year where the hottest day got to 48C where I live. That's 118F. The average UK heat wave, by comparison, is roughly 37C, or 98.6F.

The average summer's day where I live is anywhere between 35C and 45C, enough to be considered "heat wave" conditions in many areas of the world.

These are temperatures where you can barely walk for a straight twenty minutes without feeling exhausted, let alone march for eight hours straight in full plate armor, or fight for your life reliably.

Living in and doing day-to-day activities in this weather leads me to believe that, yes, it is extremely possible to be exhausted and knocked out by such heat, and while i'm no expert i'd say 60C has the potential to be fatal with direct exposure while doing strenuous activity for a number of minutes (remembering 60C is over half way to boiling point).



I think this is the reason that most of the "fattest" cities in America are in the south. It stinks working in the heat, and since people no longer have to due physical activity to make a living, they are sedentary and get fat.
only1doug: was trying to make anything personal; just trying to provide background.

hamishspence
2009-07-06, 12:21 PM
That was the minimum in Frostburn- there are no graduations for temperatures between -51F and -130F (lowest temperature recorded on Earth, roughly.

Closest I've seen are cold-dominant planes (Caina- 3d10 cold damage per round, or Auril's area of Fury's Heart (3d12 damage) Both of which seem like they would be way below Antarctic temperatures.

It would be nice to see a scale down to really low temperatures, the way there is for high ones.

Kemper Boyd
2009-07-06, 12:28 PM
When was the last time you encountered human life existing ANYWHERE near 212 F?

Last week when I was in a sauna.

Random832
2009-07-06, 12:28 PM
Let's homebrew something up - what's the damage per round for -51F so I have something to start with?

hamishspence
2009-07-06, 12:38 PM
1d6 cold, 1d4 nonlethal, per minute, no save. Partially protected characters take this damage every 10 minutes rather than every minute.

Sandstorm has a sudden leap up from d6 lethal d4 nonlethal per 10 minutes (unearthly heat) to 3d10 per round (burning heat)

With 181F for minimum Unearthly heat, 210F maximum Unearthly Heat

Extrapolating downward, making the assumption that heat and cold work in roughly the same way, it would probably be something like -80F being minimum for Unearthly cold, -51F maximum, with temperatures of -81F or lower being Deadly Cold (3d10 per round)

However, this seems somewhat unsatisfactory (under these rules, a normal man in Antarctica, even in full protective gear, would die within seconds)

Random832
2009-07-06, 12:47 PM
1d6 cold, 1d4 nonlethal, per minute, no save. Partially protected characters take this damage every 10 minutes rather than every minute.

Sandstorm has a sudden leap up from d6 lethal d4 nonlethal per 10 minutes (unearthly heat) to 3d10 per round (burning heat)

With 181F for minimum Unearthly heat, 210F maximum Unearthly Heat

Extrapolating downward, making the assumption that heat and cold work in roughly the same way, it would probably be something like -80F being minimum for Unearthly cold, -51F maximum, with temperatures of -81F or lower being Deadly Cold (3d10 per round)

However, this seems somewhat unsatisfactory (under these rules, a normal man in Antarctica, even in full protective gear, would die within seconds)

Average damage for 1d6C 1d4NL / minute is 0.35C-0.25NL/round. The difference between -51F and body temperature is 83 K. So, let's assume that this is doubled (2d6/2d4, or 1d6/1d4 per 30 seconds) at twice that difference, which would be a temperature of -190F (-120C).

I don't really have anything more to put in a table or anything at this point.

only1doug
2009-07-06, 01:25 PM
only1doug: was trying to make anything personal; just trying to provide background.

I have no grudge with you, I found nothing in your post to disagree with (in fact I found it a very interesting post).

I was disagreeing with the person who stated that there was no need for further discussion and refuting his arguements.