I've always heard that 40% of the body's heat escapes through the
head.  So, is the inverse true for cooling?  In other words, how
effective is cooling the head in preventing heat illness?  Please be
certain to reference a source in your response.

Hello--

I have carefully researched your question and have your answer.

Yes, I found that much of your body's temperature is determined by the
temperature of your head. Cooling your head is important in order to
prevent heat-related illnesses. However, the manner in which you cool
your head is also important.

An article from the Centers of Disease Control and Prevention states
the importance of keeping your head cool in the summer, "In the hot
sun, a wide-brimmed hat will provide shade and keep the head cool."

You may read this article online. The link is
http://sportsmedicine.about.com/library/bl_heat.htm

Amy Morgan, Ph.D., an exercise physiologist at the Noll Physiological
Research Center at Pennsylvania State University in University Park,
PA, said, when you have heat exhaustion, you need to cool your head
fast. She said if you use a bandana, sweatband, or towel in icy water
and leave it on your head, you will cool off quickly. She also
recommends exercising with the ice pack on to avoid overheating.

You may read an article about Dr. Morgan's statements online. The link
is http://www.bbcgf.org/far/aug2001/health.html

I found several articles in which bicycle clubs discuss why helmets
have vents. They say it's to cool your head in the summer and avoid
heat exhaustion.

One good article is "Dressing for Winter Bicycling." The link is
http://www.hiawathabike.org/graphics/pdf_newsletters/nwsltr_nov01%20.pdf

While cooling your head is good, covering your head with a cool cloth
on a hot day is not the right way to do it. The Kalamazoo County
Health Department in Michigan warns, "Covering the head with a cool
cloth can restrict the release of body heat."

You may read this full article online. The link is
http://www.kalcounty.com/msue/releases/heat-warning2002.htm

An article in the Arizona Republic recommends soaking your head in
cool water to cool down on a hot day. The link to this article is
http://www.azcentral.com/ent/calendar/articles/0514100ways.html

An article by Dr. Uchegbulem A .Eze states, "Place ice packs (use cold
compress) to head, neck, groin and ampits." The link to this article
is http://www.usafricaonline.com/ezeusafrica.html

To conduct this research, I searched the following terms: "cool your
head" heat, "cool your head" heat dr., "cool down" head dr. heat.

I hope this helps! If you need any clarification, please don't
hesitate to ask.

darrel-ga

Good answer. Permanent brain damage can occur at 105 degrees f or
more, while most other body parts can typically recover completely
from even an hour at 110 degrees F, so cooling the head is important.
The 40% of the heat loss is correct for some conditions, but it is
more like 0.004% if you are in ice water naked up to your neck. I
think the cool towel is bad because it does not stay cool.  Neil