I am in WV and the temps were in the teens last night with the wind howling and snow blowing--my little orps are about 7 or 8 weeks old and are doing fine without any extra heat in the coop.-momma has been going up on the roost with the rest of the girls this week leaving the little ones to be put back in their broody pen within the coop. 3 of them were on the big roost last evening when I went to close up. I put them in their little broody area that I close off at night within the coop. I think they need to be altogether to keep warm for now,but come thursday I have another broody hen that is supposed to have eggs hatching that will need the broody area so these little ones have a week to get ready to roost with the big girls. The cold doesn't seem to be bothering them at all.