I'm with Two shot. Last year I "had" a problem with heat, until I got a Dynaglo heater, (rip off of the buddy heater.) Great heat and low O2 sensor helps us sleep at night without the fear of never waking up.
I used it out hunting in the 12X12 wall tent with no floor with an outside temp of 10 above. It worked great! Used it in my uninsulated 4X8 portable shanty at 20 below. Brings it up to about 45 to 50 inside! I have used it on family campouts with the little guys. Kept a big old two room family tent nice an dry on the lowest setting! Great little unit for just about everything.
-Barleydog