The little buddy type portable propane heater is designed for use inside structure as a direct heat source. Due to the efficient combustion achieved using the ruby impregnated substrate, CO production is kept to safe levels. Additionally, the depletion of O2 is another issue in a closed space, and the little buddy is designed to deal with that as well. Unfortunately, the heater is an ignition source, so care must be exercised in exposing it to flammable materials/atmosphere.

I've used the little buddy in vehicles overnight and had no issues. It would work in a tent provided the venting was not excessive. At a rating of only 8000 btu, it wouldn't take much to overcome the amount of heat it can produce.