Our chickens in their DIY chicken tunnel. We live in a residential area, so to keep the chickens protected from hawks, dogs and other predators (and to keep them out of our neighbor's yard) we hook up their portable play-pen to the run and let them range.
Cold weather chickens – 8 things NOT to do to in winter!!...Personally, I think over-warming the coop should be ~ the warmer the coop, the colder it seems outside the harder it is to acclimate to that cold.
How to Introduce a New Chicken into your Existing Flock