I still seem to have gotten some frostbite on my ears... and there is also a Buff involved, argh! (But from skiing today, not running yesterday...)
Oh no! Yeesh, really cold weather is dumb.
Growing up in Minnesota, I hated wearing hats. Result: minor frostbite on my ears over the years, and resulting sensitivity. So now I have to wear something on them when it gets below ~45°.
Eep - hope mine don't get that bad, but think they already more susceptible than most- they were covered with a Buff and two hats and still got slightly frozen...
So at -18F without much wind, for an easy distance classic ski, I wore:
Craft medium-weight long undies
fleece-lined Underarmour tights
Frozen-themed Olaf spandex
Thin merino wool top
windblock Craft top
Podiumwear wind vest
Patagonia nanopuff jacket
Swix windblock jacket
1 buff pulled up over the back of my head
pair liner gloves
Neoprene boot covers
Dermatone on cheeks
I was comfortable, just needed to remember to cover my face with my hands on downhills. Also, I could still move just fine with all that on. But it's quite a long process, and if you have to pee after all that layering, forget about it.
I have found that extra layers around my core will help push some heat out to cold extremities. But I'd have lost toes by now if not for boot covers.
I had lots (but not as many because not as cold) of layers on too... including a down vest, which I almost never ski in, but kept me warm and hands and feet were totally warm without liner gloves or boot covers... think the ears just didn't have enough coverage/have already been damaged by frostbite, so are more susceptible. Tomorrow I think I'll double-buff it for more ear coverage and hopefully will go well!! (Also supposed to be a balmy almost 10F!!)
Way to rock -18F, that's extreme!!
My running PB is -27C/-17F
. Can't remember exactly what I was wearing but it doesn't sound like as long a list as Alex's. (Incidentally, anyone who thinks that the current spell in the northeast US and eastern Canada is extreme could do worse than to have a glance at the December 1989 numbers - certainly an abrupt way to introduce myself to North American winters).
However uncomfortable it might have been, I still think -27C is preferable to +40C.
It makes sense to need less for running, because you don't have as much windchill as skiing. You can do a fair bit of damage to yourself exercising at either -27C or +40C, I think. It is hard (but not impossible, as Alex demonstrates) to have enough exposed skin to breathe and not get frostbite at cold temps. Cold-weather endurance athletes also have very high rates of exercise-induced asthma, because lungs + airways don't really like breathing tons of very cold air...
Not saying 40C is fun, but I have more experience at very cold temps!
Ugh, +40C sounds more miserable than -27C. Only so many layers I can remove! Agree with Ali on the lungs; a lot of skiers are starting to wear these dorky masks that warm and humidify the air before you breathe it.
The main advantage of running over skiing at -18F is that you don't have as much wind. The self-induced wind can be miserable.
As sweaty as I am I would take 40C (at 6pm in AZ...) over -27C. Make it a humid or sunny 40C and I would switch my view.
My few experiences with running in 40+C in Melbourne (which, as in Tucson, usually comes with low humidity) are that I'm usually more or less good for 20-25 minutes and then fade quickly after that. On the hottest one of all (a 42 in 2009), it went OK on the day but caught up with me with severe cramps the next morning (presumably salt depletion). Fortunately, unlike Tucson where such heat can persist for weeks, in Melbourne it rarely lasts for more than a day or two at a time (as illustrated by the forecast for Friday-Sunday this week: 29, 41, 22).
Can certainly appreciate how much difference the wind would make skiing at very low temperatures; skiers also probably don't need to be told that in light winds over snow cover, temperature differences with local topography can be dramatic (often 10C or more difference between valleys/hollows and ridges, even in terrain with fairly small elevation differences). The only time I've run into serious trouble with cold was once when at a conference in Albuquerque, when I didn't realise before going out that the -8C on the news was from the airport, which is a little elevated, and it was more like -15C on the valley floor (and hence underdressed accordingly, and ended up close to frostbite).