My BLRW has been refusing to come out of the coop for the past week. She will go down to eat and drink, and then goes right back up to roost. I figured she just wasn't a fan of the cold/snow, and just felt happier in the coop. I finally went to really check her out after calling the girls into the run for a snack and she didn't come out. I was horrified to find her feet looking like this!!! Is this frostbite? It has been cold here, last week was -25F below zero with -50F below zero windchills. I very rarely use a heat lamp, but I did turn it out when it got that cold. My coop is very windproof and I thought well ventilated. None of the other chickens have any issues, just this poor girl. Any idea what it is and if there is anything I can do?