I think your biggest issue is taking them from the cool to the heat and back to the cool again again. They can't acclimate with those constant changes, plus the stress of totally new surroundings. It's hard on us to go in and out of air conditioning, and remember too that the air conditioner cools by removing humidity and outside the humidity is higher. They aren't used to that kind of change. At this age they still tend to huddle too, which is more for security in a new enviroment than for warmth, and their combined body heat doesn't help them cool off. So put them where you intend to keep them and let them learn it and acclimate to it. They are hot, no doubt about it. But they'll find ways to cool off if they get a chance to learn what they are.
I think if you relax, do as others have said and provide cold, fresh water, shade and some frosty treats they'll adapt very well. Toss them some cold watermelon - just cut it in half and give it to them. It contains lots of hydration for them, besides being a favorite for every chicken I've ever seen or heard of. Fans can indeed help if you have a safe way to set them up. Make them a mud puddle. They'll be scared to death of it at first, and may never use it. But cool mud is a great way to cool off, and they preen their feathers to get rid of the residual. Besides, that will help prevent mites somewhat. If you're fussier than I am about their appearance, then just find a good shady spot and put a pile of dirt in there. It can be cool too. You've got this - I have total confidence!
