And to address Newwell, we run on generator when the power goes out, and my chickens benefit from the consistent heat because of that. Otherwise I'd recommend that they be "brought in" if the power goes out and you have no alternative power source and if it's SUPER cold. That's just my opinion being a NW native and having kept chickens pretty much my whole life. They would be FINE without heat in almost all of our weather (unless we get a sub freezing dip that lasts days and days) especially with added shavings/straw in their coop. I have never lost a chicken to the cold (even without heat added) or the humidity. I keep mostly standard breeds like barred rocks, sex links, orphingtons and the like. I have, however, lost them to the heat when it climbs above 90.