is turning a tiny bit black on the edges. I'm very worried about him now. Is there anything I can/should be doing for him? Their coop is a shed we converted by putting in a pop door, 2 large windows and 4 vents. All of the vents are open but the windows are closed for winter. We open the main door (the human sized door) every day so they can come out into our yard. I've read that frostbite is a ventilation thing, but how do I know if our coop has enough ventilation? I really thought it did. Any help would be appreciated, I feel so sorry for our little guy BTW, we are in MI and its been in the teens at night lately.