I once let myself be talked into spending a winter nite in a teepee ( 15 doller blue tarp) with an open fire in it
well the buddies assured me it would be nice an cozy
turns out it was about -35 that nite, i was eating smoke all nite long plus all nite there was condensation dripping right on my sleeping bag that was rated for about -5, didnt sleep a wink, in morning i had a nice layer of ice cover my bag.........
i think there might have been some design flaws with the tepee, learned a good leason that nite