I'm not interested in reading post after post of what people do when their 'cold' winter lows are -10 to -18... I'm talking almost -40. I want people who actually have COLD winters to tell me if they heat their coops or not. I have a regular light on a timer, well ventilated, non-insulated coop.... no wind on birds. I open the coop door when the sun comes out during the day. My dumb, once beautiful, roosters' combs have all half froze from wandering outside too much. To heat or not to heat?