We've got 4 hens and a couple of roosters living in a relatively small homemade coop based on this Purina Mills design: There's venting at the top all along both the front and back of the roof that I can fit my fingers up into and feel a pretty constant flow of air. We currently don't have a heater in the coop, although we do have a water heater (more on that below). We live in Littleton, MA, and over the past week the temperature has hit single digits (with wind chills below 0) a few times. Yesterday (Sunday) we found some frostbite on one of our roosters' comb, and this morning some on the other rooster's comb (so far everyone's feet look fine, and none of the hens have any issues): I feel bad for these poor guys, and I'd like to prevent any further damage. Fortunately the forecast for the next week isn't as cold, but before this happens again I'm wondering what changes we can make. From reading lots of stuff online it sounds like moisture is the main concern rather than temperature. Here's what I'm considering: 1. Cutting a hole somewhere near the top of the coop to increase ventilation (and of course sealing it with a screen or vent of some sort). 2. Putting a lamp in as a heater. I'm not crazy about this solution due to increased fire risk, and I'm not sure that it would really solve any problems as a lamp wouldn't be able to increase the temperature to above freezing anyway. 3. Moving the chicken's water outside of the coop. Does this make sense? Are we we foolish to have the water IN the coop in the first place, and then to worry about moisture when there's a big water fount inside as well? Any other advice? Thanks.