$Unique_ID{BRK00971}
$Pretitle{}
$Title{How Can The Top of Your Head Lose so Much Heat?}
$Subject{scalp heat loss head Metabolism Circulatory blood vessels blood
circulation}
$Volume{G-20}
$Log{}

Copyright (c) 1991-92,1993   Tribune Media Services, Inc.


How Can The Top of Your Head Lose so Much Heat?


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QUESTION:  You wrote in a recent column that "you may lose up to one half of
your body heat through the top of your head".  I know that statement is true
for I have seen it many times in health columns, but I have never seen an
explanation.  People wonder how such a small part of your body can lose so
much heat.  Please do millions of people a favor and explain how.  Or don't
you know?

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ANSWER:  That's the way!  Issue a challenge, and you know I'll put your letter
in the column.  Especially when I DO know the answer.  First we must
understand that the heat of our body, which is produced by the metabolism or
burning of the nutrients we eat, carbohydrates, proteins and fats, is
distributed throughout the body by the circulatory system.  The heat contained
in the blood warms all the tissues and keeps the body temperature at an normal
98.8 degrees Fahrenheit.  One look at a diagram of the arteries and
capillaries of the scalp would provide you with the answer that millions of
people will now know.  The skin of the scalp, which is thicker than in any
other part of the body, is loaded with a rich network of blood vessels.  Most
people who have suffered a cut or laceration to the scalp, know just how much
blood seemed to flow, and how difficult it was to stop the bleeding.  This
extensive blood circulation close to the surface of the skin can lose a great
deal of heat in cold weather, particularly when the wind chill factor dips to
low numbers.  A hat or cap acts like a blanket, retaining the body heat and
preventing its loss to the cold environment.  The same anatomy can act to help
you cool off during the heat of summer, when dousing your head with cool water
leads to the process of evaporation, and helps your body disperse unwanted and
unneeded heat.  Your perspiration over the rest of your skin acts in the same
way, but the concentration of blood vessels on the top of your head makes your
scalp an efficient heat pump.

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The material contained here is "FOR INFORMATION ONLY" and should not replace
the counsel and advice of your personal physician.  Promptly consulting your
doctor is the best path to a quick and successful resolution of any medical
problem.