Do Temporary HP stack?

[orlondok]

Was looking for a place that explains this ... but not finding it ...
I am making an elven mystic theurge (very fragile with no Con bonus)
Temporary HP are going to start meaning a lot more to me ...
So basically when I have Heroes feast on (1d6+10 temporary HP)
and I cast AID on myself ... does that mean I have say 15 from the feast and then another amount lets say 8 more from AID for a total of 23 temp hp?

[ericgrau]

They stack if they are from different sources I think: http://www.giantitp.com/forums/showthread.php?194850-Temporary-Hit-Points

So 23 in your example.

[exelsisxax]

Temp HP do not stack unless at least one source says that it does. These will not stack, you will have 15.

[Doctor Awkward]

Temp HP do not stack unless at least one source says that it does. These will not stack, you will have 15.

Per the Rules Compendium, pg. 72:

Temporary hit points gained from multiple applications
of the same effect don’t stack. Instead, the highest number
of temporary hit points gained from that effect apply.

If temporary hit points are gained from multiple, different
sources that stack, keep track of those sources and when they
were gained separately. Any damage taken is fi rst subtracted
from the oldest effect that granted temporary hit points.
When those are gone, subtract damage from the next oldest
effect, and so on.

[Falontani]

Yes 23 is correct. However if you cast aid twice you only get the higher amount (looks like you already understood that)