I am having a problem with frost bite, very early stages but I can see it forming on all my hens. It is -25 but with -40 windchill. The whole inside of the coop is starting to freeze over. I have 15 hens in a 10x10 coop and a 10x10 run, it has ventilation at the top, up above the roosts and the coop door is open during the day, right now ive been blocking it off with a old jacket, which still lets in a bit of air for ventilation at night that I take on and off. The heat lamp(yes I know they are dangerous)is only on from 5 in the morning until 3 in the afternoon, just to give them a little heat and light. I do keep the water inside the coop but I will be putting it outside soon. How do I stop them from being so cold!!!!