Move them to a dry, draft-free coop or shelter
Add deep, dry bedding such as straw or pine shavings
Close gaps that let in wind, but keep ventilation above roost level
Provide a safe heat source if needed, such as a heat lamp or brooder plate
Keep heat sources secure and away from bedding and flammable materials
Offer warm water, not hot water
Increase feed slightly to help them generate body heat
Give them enough space to huddle without crowding
Check for wet feathers and dry them promptly
Keep roosts off cold floors
Use insulated walls or windbreaks around the coop
Monitor the flock for signs of chilling or frostbite
Bring weak or sick chickens indoors if necessary