We live in East Texas and have had atleast 10 days of 100+ degree temps, and no rain. Not to mention a month of 95+ temps. The chickens pant, but are relatively fine, and still laying only slightly under average. As long as they are not crowded, have sufficient ventilation, and have shade, even if its just a makeshift roof, they'll be fine. Just not metal of translucent plastic, as these are very hot.