I have no frostbite but I have had ice crystals inside the coop on the tarp. I leave the north facing screen window open about 6 inches and have vents on the roof and the sides. While I don't think the humidity is high in the coop I did remove the water & food & put them in a plastic dog crate right outside the coop. It seems this winter in general has been high humidity. The DL is a little damp but a stirring of it helps to dry it out. I don't remove the poop just mix it in. I add more leaves, grass or shaving about every 2 weeks. And I agree frozen poop is very hard to remove.I have a few girls experiencing frostbite on their combs. I spent part of today one hand covered in bag balm one hand pinning a chicken to my chest trying to coat their combs to save the rest of the large floppy combs and long spikes. My humidity gauge in the coop says 16% during the day unless it's raining/snow melting, then it goes as high as 86% during the day. The eaves on the coop are open on the south side, I don't know what else I can do to prevent more frostbite damage. I'm scooping out as much poop as I can. Sometimes it's hard because it's already frozen to the boards and I have to wait for a thaw to get that stuff and I take what I can get. Any thoughts?
My suggestion is you need more ventilation. Hard to do in the middle of the winter when there is snow and unbearable temps. Can you open up the north end? or maybe on the sides? The bitter cold doesn't bother my girls they just fluff up more.
I hope the nustock works for their combs. I had done some research on them and they said the nustock might freeze? I don't know for sure just passing on what I read. There is another BYCer whose temps haven been down to -65 at times and has a roo with frost bite on his comb. She has just left it alone & it hasn't gotten worse. I am sure it will start to heal once Mother Nature decides that we had enough of the deep freeze !! I keep an eye on my girls and thankfully no frost bite.