Wow I feel bad, my poor little chickens must be freezing! We have recently had extremely cold weather here is Oregon (cold for Oregon that is). It has been as low as 9F here and I finally put a seedling heat mat in between two pieces of plywood and put a waterer on it. It also has a bit of extra room for a couple of chickens to sit on. So the water has not been freezing, the plywood is warmer than ambient but not by much amd several chicken are roosting still anyways. Every morning when I let them out and give them some warmed treats they are rip roaring ready to go. They do not seem to think it's as cold as I think it is. They are still laying and I not noticed any frostbite on any combs yet. My coop is made of lightweight plywood is not insulated but it is fairly draft free. The other day I came home and it was about 25F and they thought it was warm enough for dust bathes in wet sand. So I don't really think this cold weather is bothering them at all. I keep looking for changes in their behavior but have seen none. For the record most of our chickens are about 26 weeks old with two of them around 18 weeks. We have 2 SLW (one roo one hen), a PBR, Polish, Houdan, Ameracauna and a BO.