I'll also use those hand warmers which I keep in my pockets so I can sit up, hands keep warm, and the heater with a sweatshirt over it keeps the legs warm. Teen temps have a way of forcing you to just grin and bear it, but at least I'm in an enclosed stand and get away from the wind.

All 24 of the other guys in the club have propane heaters of all shapes and sizes, and it doesn't bother the deer in the least. And with the sterno, during the last few minutes of the can, it pops and hisses, but no big deal.