you lose 75-85% of your body heat through your head--myth!

[calgarychef]

Hello folks, I keep reading this one and it gets repeated by every instructor I've ever heard. It's not true, the Canadian army did testing with the troops wearing cold weather gear but no headwear. So big heavy boots, mitts, arctic parkas-you get the picture. Then they measured the heat loss with the instruments available at the time and concluded that the majority of body heat is lost through the head. Subsequent and more recent testing on near naked folks proves that the head looses heat at a rate not much more than the rest of the body. The head has little fat and high blood flow so it does lose heat faster but not to the tune of 75% of your total body heat.

On the other hand when the Innuit act as guides they insist that the clients cover their heads in cold weather, and it makes good sense to me. A woolen toque is perhaps the worst way to cover your head by the way as it doesn't prevent heat escaping through your collar and does nothing for your neck. A fur hat is a good way but still not as good as a good hood on your parka, the fur hat and the hood is the bomb though! In extreme cold I'm amazed that a hood will create an area of warmth around your head that's quite nice indeed and works well to keep your face warm too, especially if it's one of those wire rimmed hoods that can be drawn in quite tight with a small opening.

That feels better, I had to get that one off my chest!

[widu13]

Old news mate, you are preaching to the converted! You still lose heat though as you say.

[Harvestman]

If you get it off your chest you will lose even more heat.

Just saying

[blacktimberwolf]

New one on me, I've always been lead to believe that we loose around 30% through our uncovered heads......one thing I'm sure of is that if I wear a hat & scarf in cold weather, I'm a darn sight warmer than if I don't..

[udamiano]

I believe the myth was originally started to get people to cover-up. As most people tend to wear layers upon layers on the rest of the body during extreme cold, its surprising how few actually wear a good thermal hat, your nose and ears are all subject to frostbite, and frost nip, so its always a good idea to keep these areas in a more shielded environment (Before anyone says about covering your nose up you will suffocate, It was meant to suggest using something like grease) On many arctic courses, one of the many thing they tell you, is to keep moving your face muscles, as this helps maintain the faces defence against the cold (Ive seen some brilliant expressions on peoples faces while doing this )

Its also surprising how much a cold head and ears interferes with your thought processes, but as you say the head losses not much more than any other part of the body.

[rik_uk3]

The head does not loose heat much (if any) quicker than any other part of the body left exposed, the excessive heat loss through the head is a myth.

[HillBill]

What they mean, which seems to be misunderstood is that if you are wearing clothing but no hat, then 75% of the heat you will lose will be lost through your head. If you are wearing a hat but no gloves then it works out that 75% of any heat lost is lost through your hands, same if you had no boots on for example.

Its not the percentage of body heat it refers to, but the percentage of the total heat lost.

[bilmo-p5]

A warm head is a happy head,
But a hot head is a liability.

[Dreadhead]

grow your own hat....

[Everything Mac]

It's all about the ushanka. I bought one online a few years ago from the Ukraine.
Trouble is that over here it's never really cold enough to wear it without boiling my brain.

Wool hats do me fine in cold weather.

Though I must admit that this is news to me too.

Andy

[Thetillerman71]

Simple to test - try spending a weekend in the forest with just a hat on and nothing else, if the myth is true you'll only loose 15 - 25% of your body heat and be nice and warm - if it's not true you'll be freezing

[shaggystu]

What they mean, which seems to be misunderstood is that if you are wearing clothing but no hat, then 75% of the heat you will lose will be lost through your head. If you are wearing a hat but no gloves then it works out that 75% of any heat lost is lost through your hands, same if you had no boots on for example.

Its not the percentage of body heat it refers to, but the percentage of the total heat lost.

that's the way i've always understood it too. if it was just a straight 75% of your total body heat being lost then you'd be very dead

[Andy BB]

I believe the myth was originally started to get people to cover-up. As most people tend to wear layers upon layers on the rest of the body during extreme cold, its surprising how few actually wear a good thermal hat, your nose and ears are all subject to frostbite, and frost nip, so its always a good idea to keep these areas in a more shielded environment (Before anyone says about covering your nose up you will suffocate, It was meant to suggest using something like grease) On many arctic courses, one of the many thing they tell you, is to keep moving your face muscles, as this helps maintain the faces defence against the cold (Ive seen some brilliant expressions on peoples faces while doing this )

Its also surprising how much a cold head and ears interferes with your thought processes, but as you say the head losses not much more than any other part of the body.

This reminds me of the quote of Brian Moore (old rugby international and commentator for you lot with no class ), well-known for his dour disposition and expression. He said "Smiling only uses a third as many muscles as frowning. Therefore smiling people are lazy....."

[Nagual]

What they mean, which seems to be misunderstood is that if you are wearing clothing but no hat, then 75% of the heat you will lose will be lost through your head. If you are wearing a hat but no gloves then it works out that 75% of any heat lost is lost through your hands, same if you had no boots on for example.

Its not the percentage of body heat it refers to, but the percentage of the total heat lost.

Aye, that's fairly much what I've been told too, by Wise Old Tibetan Monks who meditated on this very subject for centuries*. Although the figure I heard was closer to 40%, either way it's always made sense to me that the exposed bit it going to shift heat faster then covered.



*-This is a complete lie. They weren't monks at all. They were various Army instructors I've encountered. They did however meditate for centuries**.

**- Also a iccle white lie. They didn't meditate.

Nag.

[ged]

I've never heard anyone say anything like 75% of heat loss is from the head. If I had, I'd have challenged it.

I've heard a figure of 25%, and I'd just about be prepared to believe that if the rest of the body is well insulated and the head isn't.

I use a hat as a form of temperature control. If I start to get hot when I'm exercising in cold weather, the first thing I do is take off my hat.

[calgarychef]

The thing that twigged this little post was #118 of the tips stickied at the top of this forum. Not trying to stir up trouble, it's just one of my pet peeves. I always have warm headgear when I go out in the cold and it's a good idea to carry some even if the 75% might not apply.

cheers!

[Whittler Kev]

It was busted on Myth Busters. They said (quite understandably) if it was true we would all just wear hats and go naked or just modesty covers

[Gray1100]

Thanks for that not only very interesting but I've often wondered if it was true as I hear it so much!

[Colin.W]

This reminds me of the quote of Brian Moore (old rugby international and commentator for you lot with no class ), well-known for his dour disposition and expression. He said "Smiling only uses a third as many muscles as frowning. Therefore smiling people are lazy....."

This brings to mind another quote from Bill Hicks (american comedian)when people tell me smiling uses less muscles than frowning so smile and save energy. I tell them "pointing that out used more energy than walking past so save yourself some energy and leave me alone"

[Vulpes]

Not to mention though that the cold and wind beating your head in is pretty miserable to be honest. I believe a hat does make all the difference.

[Zingmo]

90% of all statistics are made up on the spot!

Z

[Nagual]

I bet the Mekon looses at least 80% of his heat...

Mekon_Big.jpg

[HillBill]

..........

[Teepee]

A souce of info for 3/4 of heat lost from the head from a dogsledding site.

Chapter 1, point 1.

[HillBill]

One way to see it accurately is just to do the maths.

If your body loses one degree of heat sat round the fire with no hat over the course of an evening, then what the stats say is that .75 of the one degree is lost through the head. With a hat on, the total loss for the evening would be .25 degrees.

If you have cold hands, put a hat on. Thats one saying i like that holds true.( unless your already wearing one )

[Andy BB]

A souce of info for 3/4 of heat lost from the head from a dogsledding site.

Chapter 1, point 1.

Interesting article - thanks.

[calgarychef]

It is indeed a good article and probably something that should be used as a training manual for anyone going into cold weather conditions. Some very good information especially about the goretex in freezing temps.

I'm not sure about the head/heat thing, I'm still not convinced. For example if a northerner wants to commit suicide one of the ways is to get drunk then go outside and open their jacket so their bare abdomen is exposed. Apparently the blood heads to that area to keep the core temp elevated and unconsiousness follows quite quickly. Unpleasant argument yes but straight from the lips of the coroner doing autopsies. The point is they don't go outside and take their hat off.

I agree most with zingmo's post, it's a good saying and one I'm gonna steal!

[Andy BB]

I can sorta see this from both sides. Sure, if you're naked you have large areas of skin exposed to the elements and there will be major heat loss from all of this. But most times we aren't naked - in general we're pretty-well covered up apart from the face/neck/head (and those of us with little hair on top are even more exposed there)! Add to that the fact that - unlike most of our "core" organs that the body protects by reducing bloodflow to other organs - the head is not well-protected by layers of muscle/fat. Or - normally - clothing. The body keeps the blood-lanes open to the head and brain; even though geographically it is an "extremity", the body doesn't regard it as such.

So - yes - in naked form, we'd lose heat - at least initially - based primarily on skin surface area, so the head wouldn't be such a major factor (and is why immersion in cold water can kill so quickly, as all of the body loses heat on soaking). However, in most "normal" situations we aren't naked, apart from the head/hands, and the hands aren't given priority by the body in terms of blood supply. Hence the significantly increased priority afforded the head as - even in extremis - the body will continue to try to pump warm blood to the brain.

[ScoobySnacks]

It's not a myth given the right situation. Is it true in all situations? Of course not. As Andy says the proportion of heat lost from different areas of the body depends hugely on the clothing. If it acts as a reminder for people to wear hats, especially the folically challenged like me, then I don't see the problem with it!

And Zingmo, the full quote (can't remember who made it, but it was someone well known) is "90% of statistics are made up on the spur of the moment, I know because I just made that one up"