Help, I have 25 chickens in a 8"X8" coop, I use the deep liter method, its about 6 inches deep. I have vents low in the back of the coop and high in the front a long with the entrance to coop. Since its gotton cold, I've notice the windows icing up overnight on the inside of coop. I'm worried about frostbite. Any suggestions or should I not worry??