[Wavery]

We have been using a Mr Buddy heater for several years with no issue. It has a carbon monoxide shut-off. We leave the roof vent open a little and there is enough air coming in under the door that oxygen levels are fine. the rising heat takes air out and new air is introduced under the door.

We use an 8' long extension hose and run it out to a separate tank outside.

I wouldn't use it with small children because of the touchy-burny factor. The slightest bump turns the thing off so fire is not a realistic threat.