thank you all, they have a walk in coop 16x8 , 7ft ceiling and the top 15 inches was just wire, and i have put plastic on that part now. I had a heating element in coop, but have moved it closer to where they roost, and ordered a heating panel. We got down to 25 in am on a couple of days, and all the hens seem to be ok, so looks like it took the brunt of the cold . I have total of 4 full size hens & the 1 rooster, 1 bantam rooster and 2 bantam hens.
Will keep eye on his comb and hopefully it will take care of itself.