We hit record lows last night with the wind chill it was going down to -20 to -30. I went to check the chickens holding my breath. (they are all bantams). They are not happy with me. Squacking up a storm! Several were huddled together in one of the nesting boxes. Two in the wooden house that is in there coop. The warmest seems to be my broody in the dog carrier! And man was she happy when i gave her warm water!!!! I gave them extra (extra!) scratch. I am keeping them locked in the coop today though, I may let them out for an hour later when i can be home to keep an eye of them.