One of my friends, John Swee, is a big outdoors guy. He works at REI and has more gear than anyone I know. If I could post a picture of my jealousy, I would. Anyway, he and I were on the Link Retreat and were discussing the possibility of sleeping outside. Note: temps this weekend were highs of 1 and lows of -13. After discussing our strategy, we began to prep for our adventure that night.
Our plan was for each of us to put one sleeping bag into another. I had a bag rated to 15 degrees and another rated to 0 degrees. John had one rated to 15 and 50 degrees. I had a little gear back I'd keep in my bag with my iPod (incase I couldn't fall asleep), small water bottle, cell phone, extra hat, and camera. Every nighttime outdoor activity requires a headlamp. Here, we're packed and ready to go.
After a few minutes of adjusting, we're in our beds for the night.
So you're probably asking yourself: "How cold was it out there?" Great question. John had already planned to monitor our situation. Here's what one thermometer said, sitting against our boots outside our bags.
The next logical question is: "How warm were those bags?" Another great question, thanks for asking. John had another thermometer in his bag and after we got settled, he was giving me 30-second updates: "65 and rising. 70 and rising. "
Finally we maxed out the thermometer - 80 degrees inside our bags. After thinking about it, it made sense that these down bags would keep in our body heat (which we all know is 98.6) and we should be able to keep warm.
It was time to call it a night. We wrapped up for our final sleeping position. This turned out to be the most difficult adjustment for sleeping in sub-zero weather. If you completely close off the mummy-bag, your breathing is tough b/c the air is so warm and clostrophobia begins to sink in. Both John and I experienced this for the first time. We figured out that if we created a "hood" with the end of our bag, we could have a sliver of cold air that quickly warmed when it reached the warmth of our bags. This fresh air was important for our compfort throughout the night.
In the end, I woke up at 5:45 and had to go to the bathroom so bad. I knew I wouldn't be able to fall back asleep, so I called it a success and took my gear inside the lodge and slept for the last hour of the night. Later, John would tell me that at 4:30, he woke up and had the same thougth. Except he got out of his bag, did what he needed to do, and got back in!! He is hardcore.
Subzero sleeping is very doable with the right gear, a little planning, and the will to adventure out and try something new.