A major skill in old-school mountaineering and other very cold weather pursuits was managing exertion and insulation so you didn’t sweat too much and ruin your insulation for later when you needed it. Much less important since the invention of synthetic wicking fabrics that still insulate when wet, but still something to be aware of and try to control.
In addition to those noted in the article, they may have other physiological adaptations as well. Per Cecil Adams:
Arctic peoples possess various physiological properties that make them well suited to life amid the icebergs, and in fact cause them to endure considerable discomfort if transported to a warmer locale.
For one thing, Eskimos are compactly built, which minimizes loss of body heat. The average Eskimo’s height is only about 5’2″, and most of that consists of a massive torso. The lower portions of their arms and legs are shorter than the upper halves, and their hands and feet are distinctly petite. That means they don’t lose a lot of heat through their extremities, which are most vulnerable to the cold.
Eskimos have a higher-than-ordinary basal metabolism rate (they burn their food faster), which enables them to keep their blood temperature at a tolerable level despite the cold. Their blood vessels are arranged in such a way that there is increased blood flow to exposed body parts, such as the hands. In addition, blood returning from the hands is warmed before re-entering the heart.
In extreme cold, some northern people are capable (via the autonomic nervous system) of shunting blood from one artery to another so that temperature can be reduced in the extremities without affecting more important organs.
Hmmm…I would like to see a cite for that one. Most physiological adaptations are actually epigenetic in nature (that is, they express or suppress certain genes that exist in the overall population at different frequencies or stages of development) and this “shunting” of blood between arteries sounds like a bit of a reach. The rest of the claims are plausible on the face, and may provide a marginal benefit that makes a difference at the extreme, but it is also the case that Arctic natives are also just very experienced in cold weather survival in a way that most people never have to develop.
There was a similar adaption recorded for Australian aborigines (not a freezing environment, no frost bite possible). All subjects remained warm when surrounded by fire in the traditional Australian aboriginal fashion. When not surrounded by fire, the AA group dropped external temperature, retained core temperature, and slept. The European group dropped core temperature and were unable to sleep.
It also simplifies things to assume that humans are perfectly spherical. Oh wait . . .
They are! (Almost.)
Can’t help but wonder what Inuit women think about being told they have “massive torsos”.
Massive torso women make the rockin’ world go 'round.
It kind of loses the cadence.
Massive torso makes the lovin’ more so.
It seems like the answer should consider exposure time. Very heavy clothing can get you through a -40 degree exposure, but for how long?
As you get up to higher temperatures, there comes a point when that same clothing ensures you’ll die from starvation before hypothermia. What’s that point?
(as an aside, it seems like diet should be a factor too, because without the right nutrition you’ll lose some and potentially all your heat).
Sounds more like the Isley Brothers.
And don’t any of you forget it! /fondly
Or, alternatively, you might just be showing your own cultural bias here. For all we know, the “massive torso” might well be seen as a thing of beauty among the Inuit.
Do we have any Inuit (or Inuit-adjacent) Dopers here who can enlighten us?
-40 isn’t all that challenging. I’ve taken up walking as a means of increasing my activity level this winter, and recently upgraded my wardrobe to better accommodation cold weather. Through our recent cold snap here the coldest I went out in was -33C and with 5 layers (synthetic base layer, thin merino sweater, fleece sweater, fleece jacket, shell, similar on lower body, plus boots/mitts/headwear) I was actually a bit too warm once I got my heartrate up. For -40 I might add one more layer, but possibly not. I was out for 2 hours and warmer at the end, even fingers and toes, than when I started. So for how long? As long as you keep moving, at least.
Obviously the issue is a bit different if you’re inactive, but if you’re not moving you don’t need clothing that permits movement.
Also note that Inuit hunters in the high arctic are active outdoors for days at temperatures Saskatoon will never see. Virtually never drops below -45C here.
My point wasn’t that -40 is specifically challenging, it’s just a temperature where simply bundling up might not keep you warm indefinitely without some external source. I thought -40 would be less likely to misinterpret because it doesn’t need to be converted.
My point is that any amount of bundling up will get you by for a little while, but how long of a while are we talking about in the OP? I took it to mean indefinitely.
Even mildly chilly temps can be deadly in hours if you’re improperly dressed, or wet, or it’s windy.
I guess what I was attempting to convey is that the point at which bundling up might not keep you warm indefinitely is going to be colder than -40.
At some point. But that point is well beyond the thickness and weight of four down sleeping bags. It would be some unwieldy clothing, but probably not as bad as, say, a suit of armor, which is also clearly not a house.
Sure, but even very warm down clothing is fairly thin and light compared to protective clothing worn in other contexts. You could put a lot of layers of down clothes on before you’d approach a tiny dot in the middle of a sea of down with such a large surface area that you’re no longer adding insulation.
The issues of moisture and being able to breath from within your clothing seem like actual limiting factors more than this. I think we could make clothing that would keep people warm in much colder temperatures, but we don’t because those temperatures are quite rare, and it would be pretty hard to accomplish anything that couldn’t be better accomplished with some kind of heated vehicle or just waiting until it got warmer.
For where winters are very cold, a complete set of winter clothing really is a functional house: Environmental protection, HVAC, egress and exit for consumables, and storage, all in a functional and robust form.
Indeed, I just felt it was useful as an extreme case to illustrate that we can build something to protect a human being from any degree of cold.
Use a substantial amount of blubber in the bundling. It works to protect seals and whales and the like from the cold, plus you can eat it and burn it to produce heat also. So given enough you can survive much longer in the cold than just with warm clothes that don’t provide sustenance or auxiliary heat and light.