Its a known fact that snow shelters are damp - I mean they are made from frozen water...
I have once built a snow coffin from snow blocks, but a Boy Scout thought it looked like a good place to sit and retie his boots and fell through. He screamed, it was funny, he thought he was falling into a crevice. So anyway I didn't sleep in it. Another time I was tenting and felt energetic so I spent an hour and a half digging a snow cave for the heck of it. On both of these occasions I did have the idea that I would sleep in the snow shelter but did not.
So here's a question to experienced snow shelter users, since I have never slept in one ( but they make a wonderful place to have breakfast or light a pipe when its windy out, and they are really quiet inside) . In my attempt to get into my sleeping bag, everything I tried led to snow getting inside the bag. How do you get into a sleeping bag in a snow shelter and not get snow inside the bag? And if you get snow under the bag, doesn't it melt from your body heat and soak into the bag? And finally, how do keep a down bag dry enough on an extended trip, like climbing Mt Denali, sleeping in snow caves?