I grew up on the east coast, in Massachusetts. I go snowshoe backpacking up in the Sierra every so often in the winter. I've built a snowcave in 7 degree weather. Jess is pretty similar, though she also spent a couple of years in northern Maine. Anyway, despite this we had a bit to learn in Montana.
At the Buffalo Field Campaign it was cold. It turns out that that valley is one of the 3 coldest spots in the lower 48 states. -40F is a routine daytime temperature. It was only -10F to -20F while we were there. Also the wind there is a major factor. Dealing with cold is one thing, but doing it routinely is different. My boots weren't quite warm enough but worked okay. It was amazing to learn that pack boots will actually keep your toes warm and comfortable at -10F with no trouble at all, and probably down much colder (if you dry the liners out every day).
Next though we went up to the North Entrance of Yosemite (many hours of driving on Ice. Montanans basically go the speed limit on Ice because they are used to it, on the flip side it's consistant ice and rarely glare due to the cold. Luckily I have a lot of experience drifting corners on dirt roads so this wasn't that big of a deal)
For various reasons we ended up getting there in the evening, so we found a dirt (snow) road up into the National Forest. I carefully parked the truck on a bit of a hillock facing downhill, so we could roll start her if the battery had issues (or ran out of juice before it started). We bundled up and made a quick dinner using some of the more instant food we had around.
In bundling up I put on my tights and a pair of puffy pants. I also put on a thin marino wool shirt, my normal marino sweater (usually all I use), my down vest, AND my backup warm jacket. I also had on my balaclava and hat, and puffy mittens with gortex covers. I was not overly warm. Jess did a little better as she has a ludicrously warm vintage down ski jacket from the 70's That was passed down to her.
We just wanted to get in and warm up, so we didn't light a fire this evening, instead we pulled out the alcohol stove. After a number of tries we realized it simply wasn't volatile at this temperature, there was NO vapor at all to light on fire, so the sparker didn't work. As I reached for the lighter I realized that wasn't going to work either. I have a few emergency matches (the truly light-wet type, not just the "waterproof" ones), but not many. Instead I stuck the lighter in my armpit ::BRRRR:: and waited for it to heat up. I then used this to light a candle, and used the candle to heat the alcohol until I could get it to very slowly and carefully light with the lighter (still wouldn't light with the sparker).
Now, I always knew lighters were not a great plan for this sort of weather, but what I didn't know was that a sparker couldn't light alcohol. I ran into this once before actually on my first backpacking trip over 10,000ft. There I sat trying to get my stove to light for something like 20 minutes as the temperatures plummeted. I had believed then that it only got to about 20 that night, in retrospect I think it probably got below zero that night (I'd spent it behind a rock to block the wind, in a nearly new Feathered Friend's 10F sleepingbag with some extra clothes on). So, if you use alcohol I HIGHLY recommend carrying a few backup matches. A sparker is not a good backup for truly cold weather.
We ate and drank some hot tea sitting in the cab of the truck, so we wouldn't get too chilled. Then we crawled into the back of the truck. I have a 5F down quilt that needs some futzing to get the down to the right spots, and Jess has a 10F down bag that really needs to be washed and is kinda flat. I'm using a gossamer gear sleepingpad, Jess has a thin one from them and a thicker but crappier foam pad. We were both also on top of a 7.5 lb felt blanket Jess made that we had spread across the platform of the truck. Lastly, the truck was closed up of course, giving us another 10 degrees or so, and blocking the wind.
We both slept fine, but in almost all of our gear and not too toasty. Our cores were fine, but both of us had numb toes come morning. As we got up we looked and realize neither of us had managed to keep our feet on our pads overnight... no wonder!
(3-inch long ice-crystals hanging from the ceiling of the truck cap)
Miracles of miracles the car turned over. The starter motor wouldn't reliably engage (glad I was on a hill), but it'd engage to turn it over once or twice and then disengage. The momentum jerk of starting it spinning again seemed to re-engage it, so it took a number of key turns before the truck started. I didn't want to roll-start it except as a last ditch, as we were on a steep snow-covered hill.
-40F is really where everything breaks down. We didn't so have to deal with this temperature, only ~-25F. Propane boils above -40F. Toyota red antifreeze in a normal mixture fails at -34F. Isobutane boils at -10F, and butane boils at 10F.
We ran into some other interesting problems too. When it's only getting really cold at night you can keep liquid water around. If you've got a large container and it's in the cab of the truck for instance it won't usually freeze overnight. There's some insulation there and a lot of heat from when we had it comfortable, it'll last through a 10F night no problem. When the day's high is -15F or something this doesn't work. Even with the heaters going much of our stuff in the front stayed solid frozen for days, even with driving for hours and hours. While we were sleeping the night it dropped to -25F I had some hot tea in a thermos, I drank some of it and what remained froze solid... in a thermos.
I learned a lot, and ironically this made me want to be in the cold MORE so I could learn more about how to deal with it. Good clothing is critical, glove *liners* are a must. Mittens to go over the liners are also a must. It turns out that having a properly shaped balaclava is crucial. Jess' worked well, but mine is unshaped around the nose. This meant that my breath escaped between the balaclava and my cheeks, thus directing it over my sunglasses which subsequently frosted over. This was okay but only because when we were in high wind it was only -10F, so I could leave the balaclava off my nose. Had it been colder with that kindof wind my nose would've been in danger.
Oh, I should mention that had the alcohol not lit we had a whitegas stove around, which is designed for using in cold weather. We just didn't want to dig it out. I assume we would've had to preheat that as well though of course.
Anyone else have some tips for cold weather? I mean really cold weather, when things like insulating your water bottle don't really help you for long.