I gave him water at first, but he threw it right out. And he looked like he was stretching his neck, bobbing it constantly. As soon as I knew about it, I took him inside and placed him in air conditioner and let him sleep. He slept for a whole day. I also brought in the rest of the flock with their cages because that day was VERY hot. Today, he's great. He's eating and drinking water constantly. I am however keeping an eye on him.
Thank you for helping me, Coco thanks you too!