I have 3 leghorn hens. I have a coop inside a shed with a door they can go in and out of at will and I close them in at night. They can free range on an acre. I have a heat lamp in the shed for the cold times. I have rabbits in the shed/barn as well. The chickens go out and stay out in cold weather. They have plenty of feed and water in the coop. Do I need to be concerned they will stay out in the cold and wet too long for their health? Will they come in out of the cold when they need to as long as it is available to them? Thanks for any responses.