I've used those jet engine propane heaters before....
They probably work better than my last experience. (Cue dream sequence music)
12 years ago, I just moved to Maine with $600 a '78 Ford 3/4 Chateau Van, '80 XS 650 Special, and cardboard box of clothes in the back. No joke.
A few months later I needed to get the van inspected and it failed. I was told that I needed new king pins. My stepfather had a garage with all the tools. So I spent about 8 hours on the ground in 10F degrees about 10 feet from the heater and froze my a$$ off. Well, the door was open because the van was so damned big it would only fit in part way. I had singed hair and frostbitten fingers (well it felt like that anyway).
You see those things for sale around here pretty cheap with ads like, "this was all that was left in the shop after it burned down" and "perfect for igniting all those oil filled rags you have in that bucket over there"
I'm just kidding of course. The story is (mostly) true. I'm just in rare form tonight, and quite possibly am "over the limit".
Maybe I should get me one of those flame throwers for the garage....
Thanks for the thought