we do things a bit different here... mine went out into their coop at 3 days, with a heat lamp of course. They've been out there having a ball and we've had no problems, even with the miserable spring we've had. They're 2.5 weeks and loving life... we put the lamp down low and have simply been raising it as they get bigger and the weather improves. The last 2 days we've been able to have the lamp of for the day light hours. hope this helps