Losing heat through the head a Myth !

An exposed head is subject to heat loss through convection and radiation plus there are a lot of blood vesels close to the surface of the skin . A good test would be to take the myth buster and put them naked in a snow bank and shoot a heat seaking missle and see where it hits them. I think that the myth here is that science is exact and unbiased.
 
I've always heard 10% not 75% anyways. Another factor is whether your head is full of thick hair or completely bald/shaven. What hair I do have left is rarely over 1/4" long so I wear head cover regularly in cooler weather.
 
mtwarden said:
probably should add this bit as well

"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."
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mkhop said:
An exposed head is subject to heat loss through convection and radiation plus there are a lot of blood vesels close to the surface of the skin ..
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I agree 100%.
 
The 75% of your heat is lost through your head may not be numerically accurate but it does emphasize for the general public the concept of heat loss. Heat loss from the body is a factor of exposed skin. So if you are dressed for winter travel but not wearing a hat you will loose a large portion of your body heat from your head.

Another way to save heat is to wear close fitting sun glasses. Your head is surrounding by hair (some of us anyway) skin, and bone. But your eyes are mostly liquid and are like an open window to your brain. .
 
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Besides, the brain needs to stay at a rather precise and stable temperature. If it cold, then it makes sense that body has to work harder at heating the head, because of the heat lost through the head.

Im not sure about the statistics and precise heat amount lost, i just put on a beanie when its cold, and lose it when i get hot. Seems to work just fine.
 
PropThePolecat said:
Besides, the brain needs to stay at a rather precise and stable temperature. If it cold, then it makes sense that body has to work harder at heating the head, because of the heat lost through the head.

Im not sure about the statistics and precise heat amount lost, i just put on a beanie when its cold, and lose it when i get hot. Seems to work just fine.
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Please read the post above yours--and you will learn all you need to know

Dr.Bill
 
I suspect that the 75% figure comes from asuming the person in quetion is kinda actually dresed .... but with their head uncovered , thats the only way I can figure anyone arriving at that kind of number for heat loss

it could be made to go close if you wore a hat but went barefoot , then the majority of heat lost would by far be thru ya feet ..
 
What about little people (dwarfs) whos head is a very large portion of total boday surface?
 
WILLIAM.M said:
Please read the post above yours--and you will learn all you need to know

Dr.Bill
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I did and it said head heat loss on average accounted for 20-30%, which is quite a bit when compared to the total mass of the body. It also stated that that percentage rises as the temperature drops, so I would say that head cover is still a pretty important piece of gear.
 
x39 said:
I did and it said head heat loss on average accounted for 20-30%, which is quite a bit when compared to the total mass of the body. It also stated that that percentage rises as the temperature drops, so I would say that head cover is still a pretty important piece of gear.
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Interesting.

The revisionists say that the claim that "most" heat loss is from an old military survival manual that says 45% or so is lost from the head and neck.

I never heard that claim. I did hear "up to half" from when I was a young Scout.

The BMJ article concludes that "Any uncovered part of the body loses heat and will reduce the core body temperature proportionally." That would mean the head and neck are nothing special - just another part of the body. (But the sole basis of that conclusion is a study of folks immersed in 17C water and given drugs that prevent shivering. http://jap.physiology.org/content/1...e216189c8075cde526cb34ee&keytype2=tf_ipsecsha )

Most of the science I find from the last ten years supports loss of up to 30% from the head and neck because: 1) the area has a disproportionate blood supply; and 2) unlike the rest of the body, blood vessels close to the surface of the head and neck do not constrict when cold. The head and neck are like a window that does not close when it gets cold outside -- not just another part of the body.

So this Phd says:

"Thirty percent of body heat is lost through the neck and head so it is especially important to cover these areas well."

CC Austin, PhD,, SAREC [Science of Anticipation*Recognition*Evaluation*Control of Health Risks ]

ANYWAY, what's the point of the revisionists beyond feeling superior? What is their advice to the newbie on the basis of their "shocking discovery" of a "myth"? Surely NOT to go into the wilds in Winter without a head covering.

I think the advice should remain, "Take an insulating hat or cap and put it on before you are really cold." 30% - or even 10% - could be the difference.
 
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wearing a hat winter and summer seems to be a good idea to me , I mean , your brain is in there , its a fairly delicate lump of fat , overheat it , itll mes up , chill it down too much , itll mess up .
 
People’s heads don't get frostbitten while their feet stay warm and thawed. Keep your head well insulated and your body won't have to shut down your extremities.

This study is indeed poor revisionist scientific history.
 
To help bust the bust:


Here's why insulating the head, hands, crotch and feet will have more effect than insulating the rest of the body: capillaries.

Those areas are very innervated and those nerves need a lot of blood and need it dispersed. Those areas, consequently, have an enormous number of very small capillaries -- capillaries that thus have a high surface areas of their own. So not only do you lose heat via radiation and convection from those areas, but more importantly, it cools the blood. That blood then gets transported to other parts of the body, cooling them. The reason shivering increases heat loss int he head is that it increases stress and consequently blood flow, taking blood from other, warmer parts of the body, and circulating it through your radiator at a much higher rate.
 
No way I would go out in winter without a hat or sleep in my bag without one during cold weather. All that being said here I am in the middle of the woods without any clothing dumping water over my head. Long story. :D

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Cpl Punishment said:
To help bust the bust:


Here's why insulating the head, hands, crotch and feet will have more effect than insulating the rest of the body: capillaries.

Those areas are very innervated and those nerves need a lot of blood and need it dispersed. Those areas, consequently, have an enormous number of very small capillaries -- capillaries that thus have a high surface areas of their own. So not only do you lose heat via radiation and convection from those areas, but more importantly, it cools the blood. That blood then gets transported to other parts of the body, cooling them. The reason shivering increases heat loss int he head is that it increases stress and consequently blood flow, taking blood from other, warmer parts of the body, and circulating it through your radiator at a much higher rate.
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Maybe a few subzero nights without a hat might make those who did the study reconsider or better yet 30’s with cold rain.
 
another worthy quote

"Head heat loss changes with how cold it is. The lower the temperature, the higher percentage head heat loss. Head heat loss is linear with temperature. At 0 degrees Centigrade, up to about 30 to 35% of heat could be lost through your head at rest."

while they may have "busted" an exaggerated claim on the % of loss of heat- all the literature still points to the importance of keeping your noggin warm :)

beyond the literature, I think anyone who has ventured outside in the cold more than a couple of times can certainly reinforce this point- there is a reason I wear a light wool beanie while snowshoeing AND carry a balaclava in my pack AND insure that my insulating layer has a hood
 
Until the days of the Kennedy presidency wearing a hat was not optional. All normal men wore hats, summer and winter.

Baked brains are as bad a frozen brains.
 
I'll keep my head covered no matter what the experts say. :)

Think about it, if you are well insulated from the soles of your feet to your chin and then leave your head uncovered...... most of your heat loss will then be through your head. Common sense would tell us that. ;)

Keep it covered and stay warmer.......... :D
 
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