if you do put a heat lamp in there be VERY SURE it is securely fastened to something that will keep it away from flamable materials. The clips that are on heat lamps are completely insufficient to keep them attached, and a fire would be devastating.
Last year, my chicks were about 3 1/2 or 4 months old when the weather got cold. They were fully feathered and adult sized, but they were still my babies. I clamped and screwed a heat lamp to one of the beams above the roost and plugged it into a thermocube that would kick it on when the temperature got down to 20 degrees and then turn it off when it got back up to 30. They weathered 2 blizzards (by Kansas standards -- -10 or so with high winds) just fine in those conditions. This year I have a couple of "Sweeter heaters" over the roosts plugged into the same thermocube. They are supposed to be lots safer, and they tend they use about the same electricity for more heat. We will see how they work.
Good luck. If they are fully feathered, and if the the temp doesn't get below 30 they should be fine.
