First Cold Weather Overnight - Question/Concerns
Enjoyed every second of it and even though it reached 0° over night I kept comfortable.I learned a lot of things and have a lot of questions.
My friend and I have been batting the idea back and forth for a awhile and we finally decided to go. He had been messing with a peapod design made from an old army ECWS sleeping bag that he wanted to test out. I had an unrated pad and a -25 overly humungous sleeping bag. He also had a Hennessy tarp while I was slumming it with a cheap yet very effective 12x9 painters tarp.
We hiked into a near state forest and set up shop about a mile in just up the hill from a pond and near a creek. We lucked out with our spot as we managed to pick the only area in the entire forest that had a downed cherry and maple tree. They were both off the ground and even though they were frozen solid and covered with snow, they were relatively dry. Long story short, they made some excellent firewood that burned forever and smelled delicious.
Come time to crawl into the hammock I had this extra wide pad so it wouldn't move around under me in the hammock. I have slept in this configuration several times in the past and never had an issue (I have just never tested it out in this temperature). I was wearing a base and top layer head to toe and I kept warm all (most) of the night. I woke up in the early morning due to cold feet that I couldn't shake warm. In the dark I inspected the problem and it appeared that end of the bag had become stiff and frozen. The entire bag had a good layer of frost on it actually but for some reason only my feet were cold even though they were still on the pad.
At this point I got out of the hammock and started my morning. After climbing out I discovered that the bottom of the bag had become frozen to the pad and I literally had to peel them apart.
Did my feet freeze because they were maybe too warm, maybe condensation built up and then froze the outside of the bag or it was just frost? I stuck my hand down at that end and the stuffing of the bag wasn't frozen or all that cold for that matter.
How did the pad freeze to the bag? Does that mean there was no heat transfer from the bag to pad at all through the night or did the 0° weather just overpower any heat exchange? If this is true why was the rest of my body so warm? If the pad froze wouldn't the bag start to freeze and get cold? I couldn't differentiate any difference in the feet area vs any other part of the sleeping bag, yet only my feet were cold. The outside foot area wasn't any more frozen than chest area. Is the answer as simple as just adding another layer of socks? I only had a single pair of smart wool on at the time.
In the very near future I will be purchasing a 20*° UQ. If I had an equal 20° TP would I be able to stay warm in 0° weather by just adding extra layers of clothing or would I need a whole nother sleep system rated for 0°? Does having a tarp with doors do anything for residual heat or is that just for keeping the elements out?