Why I heat – the human body can survive 40 degree temps without going into hyperthermia – but at 39 degrees we will go in to hyperthermia within 24hrs. And we know if we keep our homes at 40 degrees not only is it miserably cold but we will get sick. Most chickens will SURVIVE cold temps just as we can at 40 degrees. When it is miserably cold they can’t get rest because they are constantly shuffling and squirming trying to get warm/comfortable, like we would do. And like us lack of rest weakens the immune system. Then they usually wind up developing respiratory issues/pneumonia – like we would at 40 degrees. Then just like we do when we get sick – they have to have antibiotics.And also if the comb starts getting frost bit – it’s because the system is cutting off the blood supply there, so it can “attend to” more important parts of the body for survival – like our systems do when our fingers and toes start getting frost’ bite. I personally like to go to bed at night knowing my girls are comfortable and not at risk of getting sick. Besides that, there’s usually that “outcast” hen that the others reject and she can’t “cuddle” with anyone to stay warm.
We keep the heat between 35 and 40 degrees. We clean poo out every other day, to keep ammonia/moisture issues under control. And didn’t build the house “air tight” so they would have air circulation even if we need to close vents when it is real windy. We also cover the walls only around the roost with old paneling in winter(we remove it in summer) to prevent “extreme drafts” where they sleep,And we make sure they get lots of scratch feed at night before bed – it has lots of carbs which encourages the system to produce heat. Everyone has their own preferences , this is ours.
Just as humans are at 65F, science has proven cold hardy birds are "comfortable" at ambient temperatures -20F. No opinion here.
There are situations where added heat is desirable.
Do you have fragile, weak, or sick birds?
Just how cold does it get where you are???
Are contingencies in place should a power failure occur?