I'm looking for something... non-flamable. The building is pretty well insulated, and small, not very tall but has a lot of floor space. What's the best type of winter bedding? What's the best heat source in something that's only about 2 ft tall, but 4Wx6L? It's for only two Bantams, and the Roo has a single comb, that I don't want to see turn purple. Nor do I want to winter them in the house.