In our club, everyone has a heater in their stand. They have some big propane heaters, probably goin all day long. My stand is a small 4x4, which I've been heating with a can of sterno for over 40 years. Use to put it in a large coffee can, put in down by my feet and cover the legs with another hunting sweatshirt I bring up. Maybe 10 years ago, we found an old Sterno Porcelin Heater up in the attic of the hunting club. I'm the only one who uses sterno, and everyone else has a good laugh at that, but I find it's good for over 2 hrs, doesn't make noise or smell, deer have been right next to the stand and it hasn't bothered them at all, and just put it on when you need it.
When I used the coffee can, had one mistake when I was taking aim on a nice buck, shifted, shot, and he took off. I watched him go and (sniff, sniff) What's that ? Looked down and my hunting jacket had fallen on the can and started smoking. I put it out fast enough, but boy, did I take a ribbing from the guys at camp. "Hey City Boy !!! Show us your jacket !! Never quite let that one down, but this heater is safe, quiet, and throws a lot of heat your way. Anyone else have heaters ?