Hello! I have a concern about one of my ladies and I'm hoping someone can help. We've been having some really cold weather here in southern Michigan. One night we even got down to -17 degrees (-30 with the wind chill). I've been very diligent about keeping my ladies warm (but of course not too warm!) and on the coldest nights I was out checking on them every two hours. My thought was if they are not huddled any closer or spread any farther apart than normal then I must be keeping the temperature just right. I didn't allow them out of the coop during the really cold days (if it was too cold for the people and dogs to be out then i kept the chickens in too) On the coldest nights I put Vaseline on their combs. I was told to do this to protect against frostbite. This morning I went outside to find the points on Hazel's comb looking white and feeling fluid filled, like a blister. I didn't put Vaseline on her comb last night because it was much warmer (I could be in the coop without gloves and my hands didn't go numb). I had two heat lamps pointed at their roost but well out of their reach and nothing on the other side of the coop so they could get out of the heat if it was too much. Parts of Hazel's comb have turned white before but changed back to their normal color on their own. The blister-like points have me really worried! I don't understand how it could be frostbite but her comb did feel cold when i was putting Vaseline on it. I also though maybe having vaseline on the comb and then sitting under the heat lamp might have caused this but i didn't put any on her last night. Does anyone have any suggestion for what it might be and what I should do? She doesn't seem to be in any pain so I'm thinking maybe I should just let it be but keep an eye on it? Thank you for any help!