From the Bawk-tor 

Birds are amazing animals! Did you know they actually have a physiological system that helps keep their feet from freezing during cold weather? Think about it. Why can a bird stand in the snow and not freeze her feet off? It's because birds have a blood vessel system in their feet and legs that works to keep the blood from freezing. The arteries and veins are very small and run next to each other. The blood from the warmer artery blood helps keep the cooler vein blood from freezing. The feet stay cooler than the rest of the body but don't freeze - usually. There are times, however, when even these amazing fowl feet cannot tolerate the cold and FROSTBITE occurs. Frostbite happens when tissue does actually freeze, causing the tissue cells to rupture and die. This condition can be very painful and cause serious debilitation. It occurs most commonly on the Toes, Combs and Wattles where tissue is more exposed.

What can you do to prevent FROSTBITE?

Ensure your birds have access to proper shelter, free from drafts but also with adequate ventilation, especially when the weather is close to or below freezing. Ensure bedding is dry and comfortable. Use extreme caution if you are going to use heaters or heat lamps as they can ignite dust particulate in the air and start a fire.  If you don't have a lot of birds, you might consider bringing them into the garage if you don't have a good housing structure for them.

If you have a bird that develops frostbite, keep her in an area that is comfortable, out of the weather and where she has easy access to plenty of clean fresh food and water. She may require pain medication if the lesion is severe. If this is the case, contact your veterinarian for a proper recommendation. Keep in mind that any medication you use will end up in the eggs the hen is laying. Treatment may consist of warming the tissues in warm water (body temperature) if still frozen, Anti-inflammatory and opioid pain relief, and possibly medication to help with blood flow. Aloe Vera has been shown to be helpful in rabbits with Frostbite.