It appears my rooster has frost bite on his comb . I tried to catch him to put some Vaseline on it which is info I found on here and failed catch him, grrr. So now I am sitting here trying to figure out how to prevent this. I live in West Texas, the overnight low last night was low 20's. This is cold, but I didn't think too cold for the chickens, because I read a lot on here and seems a lot of people up north have much much colder temps. As far as ventilation, that was one of my top priorities when building the coop last year. I have ventilation along rafters and at peaks. I also have a wall that opens up above coop and a window that opens, but I have those closed for winter. I believe the temps combined with wind last couple days would be the cause. But we are new to chicken keeping and I am assuming this is frost bite. So I would like to know what you all think about our temps which get as low as 20 F (after tonight will be going back to 30-40's for overnight) the current ventilation, if I went wrong by not putting heat lamp in there (at what temp would you say chickens need heat lamp in coop??) do you think it could be anything else? He does seem healthy in every other way. Thank for any advice!