Today I noticed that my chickens' food was empty so I I fed them (7 of them) and as they were eating (fast I might add, because they were so hungry) they all started sneezing/coughing! I got so concerned I picked each and every one of them and gave them each a full look over and none of them have runny noses or crackled breathing, no discharge in the eyes or anything. I did notice a little frostbite on some of the combs so we put some vaseline on them. Is this normal coughing/sneezing when eating so fast?! It is winter here in MI and the temps are in the low 20's to 0. We do not have a heat lamp in their coop but so have an area in the run with a heat lamp so they have a place to go to get warm if they need to.