QUESTION:
Hello I am in the fourth grade. I live in Minot, North Dakota and my 
question is..... If you are sweating how long does it take to freeze or get 
frost bite?

                Eric H.


ANSWER from Dr. Ralph Brovard, Resident Physician
            Palmer Station, Antarctica
            Fri, 21 Mar 1997 14:01:12 -0500 


Hi, Eric.

You have asked a difficult question. The amount of time required for
someone to become frozen or frostbitten depends on a number of
characteristics such as the air temperature, how humid the air might
be (and sweating would be factored into this), wind chill, how well
hydrated you are, how efficiently your body engine is working to keep
pumping warm blood to the arms and legs, and what kind of clothing
you are wearing. Wool, polypropylene, and polar fleece materials are
much better, and safer, to wear in a cold environment (than cotton,
such as blue jeans or t-shirts) because they "wick" the moisture away
from your skin. This minimizes the cooling of evaporation and lets
you stay warm longer.  You get much colder, much faster if you are
wet...especially if you are actually in the water because of
"convection". Penguins and seals can selectively send warm blood to
their flippers in many little capillaries to keep them warm; plus
they have thick fat layers and tough skin/feathers which keep out
the wind.  Although I am not sure if even seals and penguins could
take the winters in North Dakota.  I've heard it is REALLY cold
there.  

PS Several of us here are from Minnesota.  Best wishes and enjoy the
lilacs soon.   

Regards,
Dr. Ralph Bovard