I have two 5 gallon galvanized watering cans. I have one pan with a heating element in it to set one can in to keep it from freezing. I went to Walmart today and bought the 12' long plumbing heat strip. I wrapped it around the can and taped it with duck tape. I hope that will keep it from freezing. I put a 100 watt light bulb in each coop. I don't know if the light will bother them more than the cold. I did have a 25 watt florescent light in the egg layers coop that I had come on at 4am so it would maintain egg production. I switched that one out this afternoon and put the 100 watt in there and turned it on rather than being on the timer. Yesterday only got to 39 and it has been 26 degrees all day and I collected more eggs today than any day since we got the hens in July. I got 12 eggs today.