Losing heat through the head a Myth !

[neeman]

Head heat loss is usually less than one-third to one-fifth of total heat loss. That means it is not the majority, which would be more than 50%. Head heat loss is usually less than 20-30 percent or so of total heat loss.

Think how much blood flow there is to the head and also the exposed arteries and veins in the throat.
A small small cut to the head bleeds heavily.

Even if the heat loss is 'only' 20-30 percent from the neck and head, this heat loss can be controlled by a hat and a scarf.

I know how much I can control my body head by wearing or taking off a hat.

The myth may be having too high a percentage of heat loss
But it is no myth about heat loss from the head.

 

[teacher]

Think how much blood flow there is to the head and also the exposed arteries and veins in the throat.
A small small cut to the head bleeds heavily.

Even if the heat loss is 'only' 20-30 percent from the neck and head, this heat loss can be controlled by a hat and a scarf.

I know how much I can control my body head by wearing or taking off a hat.

The myth may be having too high a percentage of heat loss
But it is no myth about heat loss from the head.

+1 .... :thumbup:

Exactly, the head is in many ways much like a heat exchanger or heat sink.... as is any part of the body where the blood vessels are near the skins surface.

 

[ejes]

 

[DennisStrickland]

well pit your pic proves you can walk the talk. i'm in agreement that good shape makes for a safer & more enjoyable outing.--dennis

 

[Gadgetaholic]

I would suggest that when it is bitterly cold you should cover all the exposed skin that you can because 90% of the heat lost from the body can easily be from wherever the exposed skin is. The head may be a bit more sensitive to heat loss due to a greater blood flow, but exposed feet in sub zero temperature can still lead to losing toes to frostbite so just cover all the exposed skin that you can!

When it is really cold I like to cover my ears - I don't need chillblains or frostbite on my ears. Warm socks and good shoes are a must - the feet are the furtherest part of the body from the heart and are therefore the most susceptible to frostbite.

If you were not wearing a shirt (or anything else on your uppper body) but wearing a hat then I would presume that over 50% of your heat loss would be from your upper torso. The head is not all that special when it comes to heat loss, just cover as much as you can like the rest of your body.

 

[Thomas Linton]

. . .I. The head is not all that special when it comes to heat loss, just cover as much as you can like the rest of your body.

The head is special. As compared to the rest of the body, if all bare, it loses 3 x the heat due to disproportionately large blood supply and lack of constriction of blood vessels near the skin when that area is very cold.

As to the point that you should not leave any area unprotected if excessive heat loss is an issue, +10

 

[RandomAyes]

......

 

[mtwarden]

^ and/or light goggles, I found out the hard way last hunting season what 30 mph wind driven snow at 0 degrees does- it makes you cry like a baby!

 

[island4bobo]

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.

Yeah, like he said.

I'm not usually one to cite the military as a fount of knowledge, but it's my impression that they're currently citing 50 percent as the heat loss through head and neck. Usually, the military doesn't just use conventional wisdom in such matters, because there are so many private research entities that rake in govt grant money to conduct exactly this kind of research, which I think, in the last 20 years, partially resulted in the ECW gear flooding the military.