Hi all,

I was just pondering the following today: why is it that when you get into very cold water, you inhale deeply? I have tried to sum up several possible reasons, but the true answer remains a mystery to me...

1) It is an instinctive reaction, which we have simply evolved with over the thousands of years;

2) On touching cold water, our diaphragm automatically contracts - along with the ribs rising. This would obviously make us take in air (because the air pressure within our lungs would be lower than outside). I'm not sure why this would happen though, I just thought that this may be a reflex caused by the stimulus (cold water);

3) Now, this must have something to do with temperature, because we do not inhale on entering warm/tepid water. It seems only to be in cold water when this odd action occurs. Could this have something to do with the fact that as our body temperature is much higher than that of the water, on touching the water our capillaries retract from the surface of our skin (but wouldn't this take a few seconds?) and this causes us to inhale...

I am only speculating here, but I would love to know the real answer! Thanks,

M.

It's a reflex reaction.
http://www.health.utah.edu/nutr/6440....Review.04.pdf
http://atlantickayaktours.com/Pages/...dwater-2.shtml
http://www.ussartf.org/cold_water_survival.htm

Ah...thank you very much! I've learned something new today! Hehe... I could've sworn there was nothing to be found when I Googled for it - oh well! Thanks again!

M.

Just gotta know where to look--in college, my minor was Emergency Medicine.

Interestingly enough, cold water also induces what's called the "mammalian dive reflex", the upshot of which is that when someone drowns in cold water, they're not dead until they're warm and dead.

Oh yeah, I read about the Mammalian Dive Reflex in one of the links you gave me - but I thought it was meant to help you survive longer.... Heh!

M.

Ps. How about a tinfoil hat for me?

All you've gotta do is make me laugh! It's just that simple!