Is it true 80% of body heat is lost from your head?

Question

I've seen people say this as if it's some scientific fact. Is it really 80% and has it been scientifically proven? I can't find anything on Google about it except random people who say the same thing, so I'm not sure if this is exactly true.

Answer 1

I'm a doctor, specifically a surgeon, but I never learned anything about this in my medical training. However I'm also a rock climber and mountaineer of long standing and I was taught specific things about survival over many years by supposed experts. Unlike the data that I use to support surgical decision making, where I review the science directly, I have not reviewed the science directly on this. I do know this much, however: the method by which the conclusion is reached involves filming athletes with an infrared camera while they exercise.

I was quoted 30% of heat is lost through the head. Not 80%. 80% would be silly. 30% is already a LOT if you consider that it represents nearly a third of your heat loss, for a body part that represents significantly less than 10% of your total body surface area. The reason that this occurs (sadly enough) is NOT because of the brain. Well... maybe in my case it's because of my incredibly powerful brain... but for the rest of you, its the SCALP. :)

The scalp is enormously vascular. Where a foot long gash in the skin of the thigh or back would be painful, it wouldn't be life threatening. A foot long gash through the scalp, on the other hand, can absolutely lead to fatal bleeding. I have seen people die like this, both in the mountains and in the city.

The heat loss through the head comes from the extremely efficient heat exchange between the scalp and the surrounding air. The scalp has EVOLVED to be a radiator just like the ears on an elephant.

At altitude, temperature management can be a lot of work. The principle is to retain warmth but not moisture. There's nothing worse than being sticky sweaty AND cold. A warm hat which breathes well, and which can cover the ears is essential. The key is to put it on BEFORE you get cold.

I hope that helps.

Answer 2

Gosh irf, if it's scientifically important for you to prove 80% vice 78% or 81%, then I suggest you continue your research. After thinking about it, I'll stick with the idea that at least a majority of heat is lost from the head because the skin is thinner there than anywhere else.

Exactly how much money should be spent to prove it scientifcally???

Answer 3

I'm not sure of the exact amount, but it is quite a bit as this is one area we do not regulary cover with clothing. This is th same reason we put caps on newborns, they can not regulate thier own body tempurature and it is important that they stay warm.. When I worked in Surgery we would even put plastic wrap over a patients head to keep them warm if they risked getting cold because larger sections of thier body were exposed. (they were intubated) Check out medical information, anethesia info too... you might find a more accurate answer there as to the % of body heat lost.

Answer 4

I heard it's more like 60%. Most of the stats that i've seen agree on about half or just over half of your body heat being lost through your un-covered head.

Answer 5

I found a cited website that claims somewhere between 30% and 50% of body heat is lost through the head here:

http://www.faqs.org/health/Sick-V2/Hypothermia.html


And another cited site here claims between 7% and 55%:
http://science.enotes.com/science-fact-finder/human-body/how-much-heat-lost-through-head-when-person-not

I saw a lot of other sites claiming about half (50%). Most likely it is not as high as 80%.

Answer 6

Yes. I'm quite sure. This is why when you're cold it's good do cover your with a hat, hood, etc. That way you don't loose heat. Ask your doctor. They'll probably know.

Answer 7

It might be true, but if you cover your head, then the heat will find someway else out of your body. I know cause if all you did was wear a hat when it is cold, you'd freeze.

Answer 8

A massive amount of heat is lost from the head, because it's on the top of your body and heat rises. When you blush, your loosing even more heat from the capillaries.

Answer 9

Try looking up"cold hands syndrome" on your search browser.When your hands and feet are cold, you will almost always feel cold in general. It is easy to keep the feet warm with shoes, but if you hands are cold, you will still feel cold. I use light cotton house gloves in the winter around the house to keep my hands warm. When they are warm--I am warm--always!

Answer 10

Yes, I believe it's true. It's possible it's higher then 80%.
The head has a thin bone (shull) and thin shin layer. The organs of the body are surrounded by tissue, muscles, bones and shin.