It's been a long cold winter for sure. Started in November this year and we've gone through a lot of wood. That said, I'm in Northern Vermont. Forecast for next 10 days is no day above freezing. Last week Monday the high was -3 F. We don't heat the coop. The chicken door is opened every day, food and water are left in the run under shelter. Ventilation is key and wind breaks on run will get them outside.