Getting ready to go deer hunting, my daughter and I, so I decided to pull the old wall tent out for shelter, a 14x16. Usually I've stayed in campers, I bought this a few years ago when my brother and a few of his buddies came out to try their hand at elk hunting so it's been tucked away since then. Anyone who has been out to CO. this year to hunt knows that the weather has been extremely mild, but to take the nip off of the cool nights and mornings I went out and purchased a dual head propane heater that attaches directly to a 20lb. bottle. My question is, how safe is it to use it in the tent? All the warnings on the box say not to use it in an enclosed area, but many reviewers openly claim to use them in a shut up garage. Wall tents breath, shouldn't there be an adequate supply of oxygen? I bought a Mr. Buddie heater for that season my brother was out here but took it back, turns out it didn't work over 9000 ft. I'm not in a position to go buy a wood burning stove for it either, so if this heater has limited use, then so be it, just want to be safe with it. Any advise?