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Anti-Frostidigitation: Heatpipe Gloves
Hettinga writes "A little casemod couture this morning, courtesy of Hongbin Ma, a professor of Mechanical and Aerospace Engineering at the University of Missouri. He has developed heatpipe-driven gloves which pump therms from your toasty upper arm down to those aforementioned frosty digits. 'Each glove contains five small heat pipes, one for each finger, that are about 14 inches long and 1 mm x 2 mm in the cross section. Each pipe consists of three sections: an evaporating section, which is attached to the upper arm area; an adiabatic section, which is between the finger area and the arm area; and the condensing section, which is attached to the finger area.' Coming soon to a half-pipe near you..."
That sounds like an idea that could equally apply to those with lower circulation, not just those on the slopes / in the cold.
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Too bad nature decides to shut it off in the hands when it gets cold.
I can't imagine that little bit of lost heat was the difference between life and death for anyone. But, the fact that we have evolved the feature suggests it was.
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There are those with poor circulation in the extremities whose bodies have some trouble warming hands and feet back up once they've gotten cold. Speaking as one of them, once my feet have gone cold, they stay that way for ages, even after getting into a warm (or even hot) envinronment, changing shoes/socks for warmer/dryer pairs, etc.
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It's actually better to keep your torso warm.
The draining of blood and heat from your hands and feet happens when your core temperature starts dropping. This is done to protect the vital organs, heart, liver etc over the non-vital, hands, feet. If you can keep your core temperature normal you can actually work without gloves even below zero (celsius). This because the body is warm and needn't cut the heatloss from hands or feet.
There was a good documentary on the Discovery channel about the very subject not long ago.
So, while heatpumping gloves seem nice, I'd go with keeping my body warm and be rid of any gloves hindering my hands.
Yeah, bring on the puns..
This is short circuiting nature, basically as we get cold extremities like the hands and fingers have the blood circulation restricted to conserve heat so our core body temp stays high. Fingers are far more robust in surviving cold than say our brains, they are also more expendable, and they also have a larger surface area to mass ratio so are costly to keep at body temperature anyway.
What it really means is that the garment that this is in is less thermally efficient than the same garment without (you will lose heat faster). It maybe handy for delicate work were you need thin gloves and warm hands in a cold environment with the only other real option is an active heating system power by batteries.
I can't imagine that little bit of lost heat was the difference between life and death for anyone
Let's say you don't have the option of going somewhere warm (ie, inside to a nice toasty fire)... Which do you have a more critical (ie, life-preserving) need for - To keep using your large muscles (legs, upper arms), which serves both the purpose of generating heat and might eventually move you to somewhere warmer; or, manual dexterity, which would only really help if you needed to operate a book of matches (something that didn't exist for 99.99999% of human history)?
Our bodies decrease blood flow to the extremities for precisely that reason. Additionally, assuming the worst, we can live without a few fingers or toes or even an earlobe; Sacrificing them to keep our core body temperature high enough seems like a viable tradeoff under extreme circumstances. The fact that we now have thinsulate and heat-packs and almost always a warm place to go nearby, so having our fingers nice and toasty seems more useful than preventing the small heat loss from them, had no effect on how we evolved.
But, the fact that we have evolved the feature suggests it was.
Although this may seem in direct contradiction to my point above, I mention it only for clarity... Not all inherited traits "evolved" in the natural-selection sense. One of the fundamental ideas behind evolution says that mutations occur essentially at random, and those that increase our odds of reproducing (which dying young does not) get passed on. However, those traits that have no effect whatsoever on our chances of reproducing can also get passed on, just by blind chance. For a trivial example, Alzheimer's disease - It doesn't affect people until they've passed their reproductive prime, so as debilitating as it seems in later life, it doesn't reduce its own chances of remaining in the population.
These gloves work by shifting some of the heat from more core parts of your body to your extremities.
So, your body notices the core temperature dropping and says "Crikey! Better shut off those extremities even more."
So, aren't these gloves self defeating? And possibly dangerous because they will lower your core temp while simultaneously reducing the options your body has to naturally fight that drop.
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Not all evolution happened in homo sapiens. I would assume most of our autonomic system developed in the rodents from the Jurassic, and were slowly refined over the next 50 million years. I'm sure for an animal padding through snow or ice it was *very essential* not to lose heat through their feet. What has happened since has been mere fiddling at the edges. Good thing we are now getting ready to take charge of our own evolution (and hack out all the legacy code such as this )
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