Let me try to get this started with some Phil-osophy, this is the way I think.
I have a mantra I bore people with every hike. #1. What goes down must come up, and #2. There’s no such thing as a small accident in the wilderness.
Backpacking is training for the main event, Mountaineering. You have to learn to pay attention to every bit of minutiae, every little detail of your route, your equipment, objective and subjective dangers.
Your sleeping bag could be your last line of defense in an emergency, your last refuge; Keep your bag dry at all costs, especially a down bag.
Don’t get into your bag with wet clothing – unless you don’t have any choice; You may get away with this if your bag is fiber filled. The only time you get into your bag nude is when you know it’s going to be warm enough or your bag is down and your all your clothes are soaking wet.
Here’s the problem, and there’s a couple of issues here. If you get into you down bag and you have wet clothing, you risk getting the down wet, losing loft, losing the ability of the down to trap and warm air, losing the insulation down provides to keep you warm. Further, wet clothing against you skin prevents any possibility of trapping and warming air against you skin, which is the definition of keeping warm in the first place.
You stay warm when dead air is trapped and warmed against you skin. Wind can blow this warm air away from your skin, (wind chill), and cool you down. This is when you put on a parka to trap the air and keep you warm.
If the outside air temperature is too cold, wind or no wind, you need insulation to trap – and warm – the air next to your skin. The colder the outside air the more layers of insulation you need.
Let’s say Squirrel is standing naked in the snow (could happen 🙂 ), somebody hands her some thermals, she starts to warm up, but is still cold. You throw her a shirt and some pants to put on over the thermals, a little warmer, but still cold. Now you throw her a sweater, some rain pants, then a parka, a hat, some gloves, a down vest, – get the picture? At some point, hopefully, she’s finally warm and cozy, still standing in the snow. Now you throw her a giant down comforter – wow! Finally toasty! No wait, somebody told her all you needed was the giant down comforter (sleeping bag), so you need to strip all the clothing off and just wear the bag? WTF?
Kind of depends on the rating of the bag, how cold the outside temperature is, whether you sleep warm or cold. You probably need some combination, but there’s no rule that you need to sleep in the nude, unless your bag is too hot, or you’re with your sweetie(?). Note: If my bag is rated 30F (comfort) that means it will not keep me warm below 45F. My zero bag works for me in the upper teens, then the sweater and hat go on, possibly a hot water bottle inside my bag.
Ok, let’s sum up.
1. Keep your bag dry, at all costs.
2. Don’t get into your bag with wet clothing, unless in a survival situation, and then only in a fiber bag.
3. It’s ok to wear clothes/coat/sweater/hat/gloves/thermals – or nothing in your bag, to stay comfortable.
4. Remember to take the 10 essentials, what? you don’t know about the 10 essentials?
5. And finally, there’s no such thing as a small accident in the woods and that backpacking is training for mountaineering, so stop relying on other people to read the map, ok that’s 3 things.
6. And don’t trust the temperature rating on the bag. (final point)
please comment, thanks, adios