Last time I used my bivi was scouting goats in the Cascades. I lost the trail just above tree line in a snow & sleet storm and had to set it up and hunker down for the night. It probably would' nt have been so bad if I had' nt put on so many miles and so many vertical feet that day. Trying to get into something dry and into my bag in that little thing can produce some HORIBLE cramps after a day like that. I think anything in 10 miles could hear the screaming. It kept me dry though, good thing because my water bottle froze solid that night and I had to chip the ice off the bivi in the morning. I have had an aversion to the thing since then though.