Hi everyone! I'm sure this isn't the right place to post this question--but, since you are on topic....this may be a silly question. I have 9 week old's outside now, they have been since 6 weeks. So, they have gone from the warmer days, to chillier days, to cooler to down right freezing days. Since they are young, they do not have large combs. But, what should I be looking out for to make sure they aren't getting the beginning of frost bite?
Monitor the humidity in the coop, if it's above 60% when the birds are in there increase ventilation...
Beyond that, by the time you see visible signs of frostbite, it's generally too late and the damages is started... That isn't to say you can't prevent further damage at that point by addressing the existing frostbite...
As for what it looks like, just do a Goolge image search for 'frostbite on chickens'