Eep, at 70 degrees I'm panicking. I don't ever let my chin room get above 60 degrees and that is without letting chins out to exercise. I know people like to say that 70 is comfortable, but it is not. Put yourself in a full-length fur coat, complete with hat and gloves, and just sit there. I would die. No picture exercising in it. My chin barn sits at 50 degrees all winter long and they love it.I have my AC set to 70 degrees until the outside world dips below it. They play in 70 degrees with no problems.