You have all those roosters in the pictures, plus hens, in that coop? How many birds total?
An excessive amount of moisture during freezing temps will lead to frostbite. Moisture comes from the birds themselves. From their breath and droppings. To avoid frostbite, the moisture has to be vented to the outside.
In the short run, do open the window you have, even during the cold weather. Venting runs counter to what we tend to think, but with chickens, more venting and fresh air is better than a tight coop. Wet is cold and dry is warm. Well ventilated is dry.
An excessive amount of moisture during freezing temps will lead to frostbite. Moisture comes from the birds themselves. From their breath and droppings. To avoid frostbite, the moisture has to be vented to the outside.
In the short run, do open the window you have, even during the cold weather. Venting runs counter to what we tend to think, but with chickens, more venting and fresh air is better than a tight coop. Wet is cold and dry is warm. Well ventilated is dry.