From what I learned in the past 18 hours, is to keep the ground cool that they walk on, they cool themselves through panting and their feet, under their wings. We are getting a misting system, programmable timer to have it come on at the hottest part of the day, and shut off when its 6pm. To cool the ground in their run, that they walk in. Also getting a mortar/paint/any type we can find of tray (lowes or home depot). You put water in it, and then several bricks. The bricks wick the water, the chickens stand on them and cool down. Also we are mounting a small fan over a window on the outside of the coop, to pull the hot air out up by the ceiling. Hope this might help you too.