Idk how they wouldn't do well in the heat? My wife worries about are chickens in the cold (we are about a 90 minute ride west of Chicago), and we had -43 two weeks ago and are 2 hens did just fine and even kept laying eggs. The one hen got a small bit of frostbite on her comb, but nothing bad. If your coop is well ventilated or insulated in my case I wouldn't understand why the heat would make a difference. When they are hot they will drink and go in the shade. All animals have natural instinct, they know what to do, and when to do it. I would take an educated guess and say you would be fine. Plus I think they are one of the best looking birds out there