I live in Wisconsin and it's currently in the mid 20's F at night. I have 4- 7 week old chicks (2 BR's and 2 BO's) in the garage with heat lamps. With temps this cold...I am afraid to put them in the coop! I've read many threads regarding this but wanted opinions based on my current weather. The coop is insulated and draft free, but I don't want to use any heat lamps in there. Thoughts?