Keeping chickens is new to me also. I live in R.I. and we had temps in the low teens and I too was nervous. I hung a heat lamp for the really cold nights and I found myself worrying more about the coop burning down (if hens jump up and broke lamp) then about the cold weather. Since then I've taken lamp down and found that the hens are perfectly fine. My coop is relatively small(3ft. wideX4ft. longX 4ft. high) but the 3 hens can keep it about 10 degrees warmer than the outside. I check on them at 5a.m. and they aren't even huddled together when it's 12degrees outside. If they were really cold they would be huddled together for warmth. I agree with oliviadehav. No drafts, good ventilation, and no moisture and everything will be fine.