tent wise, I have used the Big Buddy heater, which allows as low as 4K BTU, and as high as 18K BTU, and yes they do have a carbon dioxide shut off. I have also used a 1500W electric heater, as well as a electric blanket, both are capable of making you sweat if turned on too high. One trick is to have some foam pad to lay on, to keep out the ground cold. My Honda 3500IS ran them fine all night, and was quiet too. The big buddy was on a 20 pound tank that lasted easily all weekend. Needs to be pretty cold for the buddy heater though, since it does not run on a thermostat. Been a while since I needed the gen though, everywhere I have been has a hook-up for power.
