Winter forecast for our part of Colorado and I'm not sure when I need to put a heat lamp in the coop. I want them to get used to the cold so they will make it through the winter. We have plenty of ventilation on the upper portion of the coop so I'm not concerned about ventilation or draft. I have a small coop though fits 6 regular chickens but I have 3 silkies, 1 d'uccle and a mixed partridge rock bantam. I close up the door to the roost at night and close the side windows. They said it will get down to 26 f tonight with lots of wind and snow. Any info would be wonderful.