For the next 6 months I will have only one hen, I live in Northern Indiana and it is about to get very cold. Her coop is a raised A-frame so the bottom/floor is open air, with her perch in the top of the A-frame. I have moved it into the barn so it is out of the wind....the barn has seen sub-zero temps in the past. From my reading on this site it sounds like I don't really need to heat the coop BUT that is usually followed by statements like: the girls will huddle together and keep each other warm. My hen will not have that option. Thought?
If that's totally not an option, I'd agree that maybe some type of heat should be provided though I'm not sure about a heat lamp.