Aww poor dear! We have a girl who sits in the nest box for sometimes two or three hours at a time. Her comb is pretty small however. How is the ventilation in your coop? You want all the moist air to rise up and out but not be drafty below.Sadly, Nutmeg one of our Welsummer's got frost bite on her comb. She sat in the small coop nest box too long on some eggs. We cleaned it up and applied Blu Kot but it wouldn't stop bleeding and her breed sister tried picking on her, so she is isolated in a crate in the bathroom. Once the bleeding stops, we will re-apply Blu Kot and put her back with the group. It is sunny and 30 here, certainly not as cold as it has been, makes me wonder how long she was sitting in the nest box, my guess is about an hour. I say that because I did egg rounds before I walked our dogs and she was in there but no egg. After I walked the dog, maybe an hour, I checked and she was still in there.
So any advice for me? I am trying not to beat myself up over this as these things happen with livestock. I did decide to block off the small coop as it isn't as warm as main coop.I did check everyone else and no other issues like this.