I carried this along on a solo bear hunting trip into mountains in late December. I was hoping it would help in single-digit/ below zero nights. I was not planning to fall asleep with this lit, though just to get a little heat before nodding off or for a quick warming up if I woke up to the bitter cold. I should have read more closely about the "flairs" that the instructions warn about, because one of these "flairs" burned a huge hole in the overhead mesh of my tent (even though the heater was on the tent floor). This was not terrible, as it was far too cold for insects and the rain fly limited the impact of this. I am lucky the rain fly did not also flame up. It put a good fear in me though :). The warnings on the instructions do say not to use this in a tent (which is my fault for not seeing before the damage was done), and this warning should be headed. This really SHOULD NOT BE USED IN A TENT.That being said, this heater puts out significant heat. Excellent if used as instructed. It is great if it is truly used outdoors. Use it before getting in your tent if backpacking. Could be great for a roomy deer blind. Would be excellent for lounging in an open area during cold weather (attending an outdoor sports event). NOT for inside the tent, even if you plan to be awake when it is on. Please don't make the same mistake I did.