Coldfoot Alaska: How Cold is Cold?

Frosty after dog sledding.

Living in California I realize that my concept of what is cold may be a little warped. It rarely gets below 35 degrees even in the dead of winter. But this last trip up to Coldfoot has educated me. 
The first day I was in Fairbanks it was 0 degrees outside. At 0 degrees, the hairs in your nose freeze every time you breathe in and defrost every time you exhale. Your eyes water for no reason, and every exposed centimeter of skin feels like it's been dipped in liquid nitrogen. And after that it just hurts. Most of me was covered, but my face suffered almost instantly. I kept putting my mittens up to block the wind. At 0 degrees groceries will freeze in your car if left to long, and cars won't even start sometimes! In Fairbanks most places had parking spots where you could plug in an engine warmer, and almost every vehicle I saw had a little plug sticking out of the front of it.
When I got to Coldfoot the temperature dropped to -30, and surprisingly that didn't feel all that much colder. It almost felt warmer. That could be because it was less windy and maybe I just didn't notice. Or it could have been because I was better outfitted with snow pants, and something to cover my face. It kind of hurt my eyeballs a little though. And again, if I took my mitten off for a second, my hand was frozen. My brother says that at -30 and below the thing you have to understand is how quickly you can get frostbite. At higher temperatures, it takes longer to freeze you fingers and toes all the way through. But at super cold temps it sometimes only takes a minute or two. That goes for the skin on your face, and your ears etc. 
My advice to those who plan to be out and about in the ultra cold is to be very aware of any exposed area of your body. Most of the covered areas were toasty warm, but when my face started to hurt, or my ears became numb, or my fingers icy,  from trying to manipulate my camera I immediately adjusted to the situation. Sometimes that meant pulling my hands inside my jacket, or inserting them between my neck and my scarf where it was warm. Sometimes it was pulling my parka hood completely over my face for a few seconds, sometimes it meant going inside and getting a warmer hat, and then wrapping an extra scarf over my ears. The thing to keep in mind (at least what I have been told) is that it takes a lot longer to get frostbite on parts that are covered. It may not feel any different (i.e. your hands might still feel cold) but it does matter.
My last two days in Coldfoot hovered around 30 degrees. When I stepped outside the first morning  and it was 17 degrees it actually felt warm! Like I didn't bother to zip my coat or put a hat on. I wasn't trying to be "tough" it just really did feel warm. As the temperatures climbed another strange thing started happening, all my clothes started to get wet. My mittens, my boots (which were OK in negative temperatures) got soaked, and then froze into a block of ice, my scarf got sweaty and so did my hair under my hat. Then when a big gust of wind would shoot up the valley all of it seemed to freeze on my body. The coldest I was the entire trip was the afternoon the temperature stayed about 30 degrees. I felt wet and cold, and my fingers and toes ached. That didn't happen at negative temperatures.
I've concluded that some of the difference must have to do with a.) the humidity in the air. At -20, there is almost no moisture, so most of the air around your body may be cold but it is dry as well. At 30 degrees that's all different. There is much more moisture in the air, and b.) Everything is wetter when it is warmer. If you don't have waterproof gear then you are in trouble. The snow is stickier, surfaces are wet, and that accumulates on your boots, in your hair, on you hat, etc. It is just more uncomfortable. Like being in a drizzly rain.
I am clearly not an expert on cold temperatures, having only spent a week up there, but I think that it was helpful to have someone explain to me what's most important at what temperatures. Bottom line:
Utra cold = cover up EVERYTHING.
moderately cold = Waterproof gear (boots, mittens, pants)