Celticdragonfly
Crowing
Chickens body temperature run in the 106 F range. 10 degrees higher that we do. Actually, new studies show that 98.6 F is not correct for humans. Put your hand under a wing. It's pretty darn warm under there. Dry birds are the best. Proper ventilation is key. ...
I am pretty sure more chickens have died from FIRE in a heated coop than from the cold.
Disclaimer get cold hardy birds.
Heh ... I live in Texas. I worry far more about the heat than the cold - even with non cold hardy birds, they're not going to get too cold out here, I do not need to heat a coop. I avoid breeds listed as cold hardy, because I fear that means they won't handle the heat. I worry about the ones with small combs.
The other thing that gets dead chickens in a coop is people who think putting an electric fan out there helps with the heat. Chickens are not mammals and do not sweat. Indoor fans aren't designed for outdoor coops, and bits of bedding and dust can build up and cause fires.