Myth: You lose most of your body heat through your head.

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12-23-2009, 13:20
Take-a-knee

Quote:

Originally Posted by Stumblefoot

I know while in my hammock that I usually cover my head with a balaclava or wrap a fleece scarf around it to help stay warm. I had always heard that most of my body heat is lost through my head. I read an article that said even the US Army is wrong in their survival manual when they recommend keeping the head covered in cold weather because "you can lose 40% to 45% of body heat from an unprotected head." :scared:

This myth most likely stems from a 50-year-old military study in which participants were exposed to extremely cold temperatures while wearing arctic survival suits that came to their necks. When heat loss was measured, most heat escaped from the head, which was the only part of their bodies not covered. Experts say that if you performed the same study on people wearing only bathing suits, they would not have lost any more heat proportionally from their heads than from any other part of their bodies.

So the head is not special when it comes to getting cold. Any body part that is exposed to cold weather will cause a drop in body temperature. I guess that's why we have UQ's and TQ's. My bald head still needs some type of covering.

Comments anyone?

This is a bogus assertion, the Army study is correct. All of the arteries and arterioles in your body have both receptors to both dialate and constrict, except the ones feeding your head, they don't constrict, so as to maintain consciousness obviously. All arctic paratroopers agree on this!
12-23-2009, 13:31
UncleMJM

Quote:

Originally Posted by KerMegan

KM (yes, I am an agent of Satan, but my duties are largely ceremonial...)

That explains your expertise in the area of mass consumption of firewood by campfires and interest in practicing making sparks in taverns. :D
12-23-2009, 13:33
Hawk-eye

Quote:

Originally Posted by UncleMJM

That explains your expertise in the area of mass consumption of firewood by campfires and interest in practicing making sparks in taverns. :D

There's gotta be a good story behind that! ;)
12-23-2009, 13:38
millarky

When I was a kid and complained of cold feet, Mom would tell me to put on a hat. Darned if she wasn't always right. But I still am going to try the wrist warmers around camp. I don't like gloves.
12-23-2009, 15:35
Doctari

OK, wrap everything in high quality insulation, leave an opening at the TOP, Yes, all the heat will escape thru that "Hole". leave your tush exposed & put a hat on, guess where the heat will escape from.

IMHO the test is flawed. Like Cannibal, I don't have any natural insulation, and indeed my "cold weather gear" at work is a ball cap. Not because I think all of the heat leaves thru my head, but because it is the most sensitive area unprotected if I am hat free (I wear short sleeves & thin cotton pants to 30ish).
12-23-2009, 16:20
Scottybdiving

Check this out. It's on the internet so ............ According to this article, the onset of hypothermia changes the equation.

From the Wilderness Medicine Newsletter

Quote:

Now, what about hypothermia and heat loss through the head?
If the hypothermia victim is not shivering, they are at rest, and the heat loss through the head remains about 7%. But, this is important, if they are shivering, the percent of heat loss via the scalp can increase to upwards of 55%, so protecting the head well is a very important part of treating the hypothermia patient. And as you can imagine, the primary defense against the cold and hypothermia is vasoconstriction of the peripheral circulation, this shunts blood to the core, reduces circulation to the skin, and increases the percent of heat loss through the scalp.

The difference is that the shivering hypothermia patient is indeed exercising, but they do not vasodilate the peripheral circulation; the shivering muscles increase metabolic demand and cardiac demand so the patients do increase their cardiac output; therefore, they do increase cerebral circulation; therefore, they do increase the percent of blood loss through their head.

Treatment of the hypothermia victim:
Remove from the cold.
Get them dry and keep them dry.
Insulate from the ground.
Hypothermia wrap:
Re-insulate with dry insulation.
Cover and protect the head from further heat loss.
Cover and protect the hands and feet from frostbite.
Surround with a windproof and waterproof layer.
If conscious, feed warm, sweet liquids.
If unconscious, evacuate and handle very gently to prevent ventricular fibrillation.

As a S&R diver, it has always been accepted, whether fact or myth, that 1/3 of your heat loss in water is through your head. Of course heat loss is 32 times faster in water than air. Most dive physiology information comes from the Navy.
12-23-2009, 16:30
canoebie

I realize it is dangerous to postulate generalizations from individual experience, however; in all the years of canoeing, wood cutting, ice fishing, backpacking etc. that I have had in my 57 years of life, the easiest way to regulate my sense of being warm, hot or cold is by how much insulation I have on my head. I have lots of hair on my head and a full beard. I still need a hat when I sleep in the cold. :) Keeps my feet warm.
12-23-2009, 17:07
Gracadruid

Hey all, just joined and found this post, checked with the great oracle GOOGLE, seems to be a popular topic. Here is one of many articles out there.
http://www.healthline.com/blogs/exer...t-through.html
All I know if my feet are covered and my head is covered I am warm, so do I need to wear anything else:rolleyes:
Merry Christmas and Happy New Year
12-23-2009, 17:31
DuctTape

Quote:

Originally Posted by Coldspring

I don't think we lose most of our heat there, but if that is the only uncovered area it will be where most of our heat is lost!

Bingo! This is exactly what I was thinking when I read the article on the subject a year or so ago. I think the mythbusters began with a premise which was not the original claim thus easily refuted. I always understood the original premise to be based on the fact that we are clothed and the 40% loss took that into account.
12-23-2009, 17:50
Stone

Quote:

Originally Posted by Mule

I agree with Cannibal. However, it's absolutely necessary to keep your body core and brain warm. True, from what I have read, the brain will cut off blood supply to the hands and feet first, then the limbs in order to keep the vitals within living temps. When I feel my hands or feet getting cold, I cover my head and my shoulders for sure. Much blood is pumped to the head and it does lose a lot of heat, also your shoulders.

I honestly think that you are nailing the subject on the head. The brain is the "Master Control" it will do whatever it needs to protect itself at the expense of the rest of our body.

Side note....who has read Jack London's "To Build a Fire"?

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