Hi. I live in Ma and this winter was the first my chickens had to live through. The breeder I bought my young pullets from told me it is lethal to heat the coops. I looked at his breeding pens and he told me as long as they can get out of the wind and weather and they have a place to roost at night, you'll have no problem. He was right, we got through the winter with no issues. Keep in mind that other parts of the country get much colder than around here, so others may heat their coops but you should not have a problem. Just think of the owls and hawks that live outdoors, pigeons that live where ever than can and they make it year after year. Good luck with your birds, you can't go wrong.