You can use an Oil Lamp to keep warm. I saved a few of my soup cans and they fit perfectly on this mason jar oil lamp. You have to cut both ends off of the can. It focuses the heat together and it does get very warm. Also, it doesn't seem to use much fuel. This one has actual oil made for oil lamps, but I have some kerosene saved back (my kerosene heater wick was used up and I couldn't change the wick) that I will use in my oil lamps for this. I have several of these made up and ready for if the power goes out. Thinking for the bathroom. I have a Mr Buddy Propane Heater for the living room, with curtains on the doors to close if I have to keep heat in there. Getting prepped for winter.