I too, have a Leghorn named Daisy :) and frostbite was a worry for me here in Boise, ID this winter as well. This one in particular has been the coldest for a long time, down in the singles and occasionally dipping below 0F. It would seem we are finally coming out of it and temps are staying in the twenties now at night which means frostbite is no longer a danger. As soon as it started to get really cold though, I pitched a thick layer of hay over the wire floor in the coop (my henhouse is probably big enough for 6 and I have 5) and closed the ramp door at night, leaving the side door cracked so they could hop out in the morning and the sliding board vent at the top cracked a couple inches at the furthest end to keep air flowing. Stagnant, moist air caused by chicken CO2 is the leading cause of frostbite. I also used vaseline, just because I researched it well and found that while a few people think it is bogus, alot of people felt that it helps. It also moistens the skin and here in Boise our winters are so dry the combs would be chapped, kind of like how our lips get chapped. I feel that the biggest thing about vaseline that I found was, the thicker you lay it on, the better it works. It acts like a second layer of skin. So if you just put a thin wimpy layer on, it won't do much good. I don't think it is the be all end all, but I feel like it helped. My Leg's comb did start to turn a little white on the tips, but the dead skin will slough off eventually. You can add a low watt bulb to the coop, but I don't light either and don't intend to. I think insulating will be a better bet, and pitching a nice thick layer of straw helps. I thought of stapling a section of car window sun reflector to the wall. Maybe for next year. Yes, do keep an eye out for infection in Daisy's comb or any open bleeding. If it does crack or bleed, I would sponge it clean if you can with some warm (not hot) salt water and use some neosporin on it. Good luck.