I recently received an email with the question: “Is it better in cold weather to be curled up in your sleeping bag in the fetal position or laid out straight?” Since it is winter and sleeping outside anywhere in the continental US is going to be cold - even the bottom of Grand Canyon can get below freezing this time of year - I decided this would make for a great topic.
So for your next adventure in Yosemite or the Rockies, here is the short answer. “Laid out straight.” The only time you should be in fetal position is when you are in a corner rocking back and forth.
Now the long answer and some tips on how to keep warm in your sleeping bag.
1. Insulate yourself by wearing as much clothing as possible, especially around your core (stomach, back and chest). The more layers you have, the better and if you get too warm, you can remove clothing.
2. Make sure you have a bag that fits you. A bag that is too large or too small is not going to work as efficiently as one of the right size. A bag too small will have parts of you hanging out. A bag that is too big will leave you with too much empty space, requiring more area to be warmed up by your own body heat. Fill up that space with extra clothing , leaves or water bottles filled with warm water. Anything you can use to make the area smaller. For those of you that are vertically challenged, bags are made in shorter lengths - 60″ and 65″.
3. Wear a knit cap to bed. Forty to fifty percent of your body heat is lost through your head, even more if that is the only part of your body exposed to the cold. Also make sure to keep your neck warm.
4. Be sure to keep your face outside the bag. When you breath inside the bag, you exhale moist air, creating a damp, clammy atmosphere. If your face gets too cold, put on a face mask. By the way, this is why you do not want to sleep inside your bag in fetal position.
5. Make sure you have a good sleeping mat with proper insulation and that it is positioned in a way so you will not roll off of it in the middle of the night. Check out the Big Agnes line of sleeping bags. Their system is such that the pad slides into a sleeve on the underside of your bag so no rolling off.
6. Don’t go to bed cold. Before hitting the sack, warm up by doing some pushups, jog around camp, do some jumping jacks or whatever, just not to the point of sweating.
7. Snuggle up with someone else. The more bodies there are, the more body heat. And we will leave this suggestion right where it is!
8. If none of these suggestions work, you need a new bag.
9. One last tip - if you need to pee in the middle of the night, do it! You are wasting body heat by trying to keep that amount of fluid warm, and wetting yourself is only a quick fix.
