We may get into the teens this weekend, so I have tried to winterize the coop a little, more for my peace of mind than anything else. Everything I read says chickens are hearty and will not freeze as long as they have food, water, and draft-free shelter. I have added a heat lamp, in case it gets really cold, but I don't want them to get used to it.
This morning I gave them some leftover spaghetti, a hen house favorite. Just like starchy worms.