I have Rhodies and Ply Rocks which I chose in part for their winter hardiness. It has been quite cold here in New england this last week. Yesterday was the first time I checked them and they were in the coop during the day. I was low teens with extreme wind chill. Although when they saw me they all came running out and wanted to freerange. I have already done the following to protect them from the cold. Rigged a homemade heater to keep their water thawed, working great. Covered their run with straw to provide a barrier between their feet and the ground, to keep them drier too. Covered most windows and ventilation openings on coop to keep cold wind out. Still a couple small vents open. Applied petroleum jelly to their combs to protect from possibility of frostbite. Mixed their feed with about 25% scratch to help them warm themselves. Covered parts of the bottom of the run with plywood so they have protection from the wind if they don't go into the coop during the day. I think I have done everything I need to. When I check them at night their feet are always warm. I really don't see the need for a heat lamp in their coop. I have never found them huddled any more than they always do when they roost at night. I guess when we are cold we think they must be too. I am pretty sure we have this covered but I'm open to suggestions. Here is the coop sans run...sans winter...sans cold!