Dew point. When you sweat your skin will rapidly drop toward the dew point. Where I live it varies thru the year from below 0 to about 80, always below the air temp of course. When you don't sweat your skin approaches the sometimes much warmer air temp.
30 degrees air and 30 degrees dew point right after a snowfall is sweater and pants time. This morning the dew point is only 10 degrees so I have to wear a coat although I didn't need to zip it up. No wind helps.
A highly effective way to get killed doing winter sports is to build up a massive sweat and then completely stop moving before drying out... An air temp of 10 degrees is laughable and more or less comfortable if you're not sweating, but a dew point of 10 degrees if you're all sweaty will quite effectively give you hypothermia and kill you. Or the hypothermia will make you stupid, and then everyone will wonder why the heck a smart guy was walking along the cliff edge etc. Sweating in the cold is very dangerous. I usually don't wear a coat while I snowshoe hike (although I carry it in the backpack), wearing gloves and a hat and goggles but no coat always feels weird for the first time each season but you get used to it quickly.
Dew point. When you sweat your skin will rapidly drop toward the dew point. Where I live it varies thru the year from below 0 to about 80, always below the air temp of course. When you don't sweat your skin approaches the sometimes much warmer air temp.
30 degrees air and 30 degrees dew point right after a snowfall is sweater and pants time. This morning the dew point is only 10 degrees so I have to wear a coat although I didn't need to zip it up. No wind helps.
A highly effective way to get killed doing winter sports is to build up a massive sweat and then completely stop moving before drying out... An air temp of 10 degrees is laughable and more or less comfortable if you're not sweating, but a dew point of 10 degrees if you're all sweaty will quite effectively give you hypothermia and kill you. Or the hypothermia will make you stupid, and then everyone will wonder why the heck a smart guy was walking along the cliff edge etc. Sweating in the cold is very dangerous. I usually don't wear a coat while I snowshoe hike (although I carry it in the backpack), wearing gloves and a hat and goggles but no coat always feels weird for the first time each season but you get used to it quickly.