All, My concerns about our coop design were confirmed the night before last when my ladies contracted frostbite. We were at a point of no return on the construction this summer when I realized we had some major flaws. Now it's remediation time. Our coop is 3.5 X 7.5 feet, but limited headspace. We installed a wall vent on the south side of the coop, but it's right next to the roost, as are all the windows. We can adjust or close the flanges as necessary. We added a roof vent yesterday, hoping that would solve our issues. I'm not sure it has, as the hens' combs look worse today. Do we need to add additional roof vents? It's not a large coop, but the ladies do sit at the lower end of the roof very close to the ceiling. We have a poop board, which I have resolved to clean every day if possible. The coop and run both use sand and there is stall clean mixed in with the sand. I usually leave at least one window open during the day. We have 6 hens. Attached are pics. Thanks for the help!