I have 13 silkies outside in an insulated coop, no heat lamp. They have been handling temps in the single digits very well. In fact, today it was -1 this morning and they all stayed out of the coop in the run for a few hours. Now, we have had TONS of snow here, so that snow has created somewhat of an igloo around the run which blocks the wind well for them. I just wanted to mention this because I see many people being told not to get silkies if live in New England. I think if you have enough to keep eachother warm and a somewhat warm/dry place for them to go, they will do just fine. So far, mine are.