The temps have been unseasonably cold (in the teens) here in upstate New York, and when I opened the coop three days ago, the chickens didn't want to go out - understandably so. And, yes, there was some snow on the ground. So I closed the door and have kept them in ever since. Last winter was brutal here, and the chickens were indoors for months. But I had fewer chickens and was new to keeping them. Closing the door and having two tungsten lights on keeps the coop significantly warmer than the outdoors, so opening the door would drop the indoor temp. The temperature is supposed to go up in the next few days, but the whole winter is ahead. At what temperature should I open the coop door and let the chickens have the option to go out (knowing that those inside will be colder)? What do you do in the snowy wintertime?