Friday night it's going to get down to 15 F. My coop lean-to is not insulated its ventilated well I need reassurance that the chikens will be fine. The roost is a 2 by 4 they roost on the large flat side and I did take some old carpet and staple to the roost to help keep their feet warm. I don't have any heat source on the water or in the coop.