How does someone survive going from a hot sauna to a cold swimming pool?

[Hazzardevil]

Over the christmas holidays I was given homework. :smallfrown:
And as typical of me I forgot about it.
And now it is due in tomorrow.:smalleek:
So, does anyone know how you survive going from a hot sauna to a cold swimming pool?
And why would you be in any danger doing it that would make people think you could die from it?

[Feytalist]

Just ask any Finlandian. They're the ones insane enough to do things like that :smallbiggrin: I've been told it's actually quite healthy, but the reason escapes me at the moment.

[Greenish]

Swimming pool? For an authentic experience, you need a hole in the ice of the lake (or the sea).

How do you survive it? By not dying, mostly. It puts some stress on the circulatory system, and is not recommended for people with heart disorders.

[Yora]

Why would you die? There's no reason to suspect that you would.

[pffh]

You become tingly all over and that tingly feeling is your natural magical resistance to cold kicking in.

[Reluctance]

The only thing that came to mind when you mentioned that was paradoxical stripping. Where, thankfully, the first result when I googled it was this (http://playak.com/article.php?id=141). I don't know how helpful it'll be, but it might at least jump-start your brain.

[KuReshtin]

You don't die on account of you only being in the water for a short period of time, like 30 seconds up to maximum a minute, and after being in a hot sauna, your body temperature has risen enough that hypothermia will not be an issue.

however, as has been mentioned, people with heart problems should not dive into a hole in the ice after having been in a sauna as it will put a lot of strain on your heart since your blood vessels will contract due to the cold, and the heart will have to work harder to get the blood through your system.

Or something like that.

Bottom line: if you don't have a weak heart, going from hot sauna to ice cold water will not kill you.

[Tyndmyr]

*shrug* I did it repeatedly for the giggles. It's a bit of a shock, but quite refreshing. Definitely worth giving it a try.

[Kneenibble]

If you read accounts from the late 19th century of encounters with a variety of Indian groups in Canada, you see plentiful references to this very custom: particularly in winter, after a long drench in a sweat tent set up near a lake, the Indian then ran out naked and plunged himself into a hole in the ice.

The Finlandians and most others on that half of the Arctic circle who practice it laud this activity as supremely salutory; and the aforementioned colonist writers also sometimes suggest that the Indians tended towards ill health after the custom was discouraged as savage.

I, for one, prefer the steamed lather of a long run and a cold shower, but the principle is the same.

[Manga Shoggoth]

So, does anyone know how you survive going from a hot sauna to a cold swimming pool?
And why would you be in any danger doing it that would make people think you could die from it?

I suspect that the "danger" is hypothermia due to the fact that your blood vessels are heavily dilated from the hot sauna, which will increase the heat loss through the skin.

In that case you survive going into a cold swimming pool because the blood vessels in your skin will very quickly constrict to reduce heat loss.

(Incidentally, one of the dangers of getting drunk in the cold is that the alcohol causes vasodilation, and so potential heat loss and hypothermia. People think alcohol warms you up - actually, it doesn't. The extra blood to the skin makes you feel warmer, but you are actually losing heat faster.)

Remember to wrap up warm...

[Zaggab]

As I recall it, the explanation to why it's dangerous for people with heart disorders to do that is because you get a huge activation of the sympathic nervous system (the "fight or flight" part of the autonomous nervous system).

This will, among other things:
1. Constrict peripheral blood vessels, increasing blood pressure
2. Increase stimulus to the heart, increasing heart rate (though the heart rate might initially be reduced due to decreased venous return)

This will put a stress on the heart that can result in arythmias and increase oxygen demand, while decreasing circulation to heart, resulting in possible myocardial ischemia.

The reason you survive is because most people are healthy enough to just get a kick out of it. Preexisting heart disease is probably required for it to be dangerous in any way.