Hot-headed?

December 13th, 2007

Gorky ParkJohn has returned to the topic of hats, an important one as the temperatures plummet. We had a little to and fro about this a while back… Golly, it was four and a half years ago

One question I raised then, as yet unanswered, is why the term millinery, describing women’s hat-making, seems to have no male equivalent. Still a mystery… though I do now know that the word comes from ‘Milan’. Perhaps the early artisans of male headgear were in a location with a name less suitable for such adaptation. Luton, for example, used to be a big hat spot, I gather, but perhaps didn’t inspire the same fashionable frisson

Well, I have a new hat-related question for you now: What’s all this about losing half of your body heat from your head? Or two-thirds, or three-quarters? Is this an urban myth?

I’ve heard variations on this theme all of my life, and often wondered whether one would really be comfortable walking around naked in mid-winter as long as one was sporting a decent balaclava, as this would seem to imply? I have not yet put it to the test.

And, given that your head is only about a tenth of your body’s surface area, if you were really going to lose two or three times as much heat from it as from the rest, each square inch of head would need to be radiating twenty or thirty times as much heat as a square inch anywhere else, which seems unlikely.

But perhaps you do lose most of your body heat from your head because, well, the rest of you is normally well insulated by clothes, so where else could you lose it from? I imagine I’d lose rather a lot of heat from my left clavicle too if I decided to adopt a daring mid-winter off-the-shoulder look.

All most mysterious, and I’ve always suspected it of being an old wives’ tale — probably brought into play when the story that a swan can break your arm with one beat of its wing no longer has sufficient impact. My minimal web searching would suggest that in most normal circumstances the head loses heat at about the same rate as everything else, but that the flow of blood in the scalp is not varied to the same degree to compensate for temperature, so under certain extreme circumstances, such as when exercising vigourously in very cold weather, you may lose a disproportionately large amount from the head.

Anyone have more authoritative knowledge about this?

In any case, being somewhat follicly-challenged, most of my hat-wearing is for the purposes of keeping off the sun, rather than protecting me from the biting winds. After my rather chilly walk home tonight, however, I may decide to branch out a little. Perhaps I’ll try that balaclava experiment…

Posted on Thursday, December 13th, 2007 at 12:43 am and filed under General.

2 Responses to “Hot-headed?”

  1. David Says:

    I only poked around for a couple of minutes, but this made sense to me: http://soundmedicine.iu.edu/segment.php4?seg=335 (with a swimsuit, only 10% escapes through the head)

    David

  2. Jim Henderson Says:

    Yes it’s an interesting question. I am interested in it from the perspective of mountain rescue. Here is an interesting post about heat loss via the head in relation to hypothermia.

    http://wildernessmedicinenewsletter.wordpress.com/2007/02/14/heat-loss-through-the-head-and-hypothermia/

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