Our feathered babies are about 8 months old. They've been very healthy and happy. It got down to about 20 last night. Our rooster was in the doorway to the little coop and he got frostbite on his comb and he couldn't stand this morning. His body was so cold to touch. I brought him inside and warmed him up. His comb is much better, he's eating, drinking and pooping. He's no longer lethargic. His right leg is fine now but he won't stand on his left leg nor will he stretch out his toes. He has some small blackened spots on his foot which is more pliable when I massage it now but he acts like he can't move his leg at all. What do I do?