Shade. As deep as you can provide. We put up shade cloth all across the south and east corner of the run, which helped immensely. This year we are growing gourds along the fence (but chickens will eat the greens, so the are started about 2ft from the fence). The gourds aren’t growing as thickly as needed, but the certainly are interesting. We additionall added more metal roofing over the run, for more shade and for more dry run square footage for dust baths. Our coop is elevated about 2.5’ above ground, so good shade under there. The coop and run are directly behind the barn, so by 2 pm the run is completely shaded, so they miss the intense afternoon heat.
since they tend to not eat or drink as well in the heat, even with shade, I’ll give them wet feed n the afternoon, once the run is completely shaded. This helps keep them hydrated better, and they eat well before going to roost. I’ve noticed they lay better when I give them wet feed on the hot days. I use a galvanized round feed pan from TSC, put in feed and cold water. Let it soak it up, stir, add more water if needed. Then I push ice cubes into it so they will melt and keep the wet feed cool. It gets put into a shady spot and they converge on it immediately. You can really see the pecking order at this point!
we keep the large 5 gallon galvanized,double-walled waterer shaded using a piece of OSB leaned up against the barn, in front of the waterer. The waterer is up on blocks to keep it cleaner from all the dust bathing. So that waterer doesn’t get hot, as chickens won’t drink hot water.
@aart has good suggestions above with ice and cool water in shallow trays. Some chickens figure out to walk through the water to cool down, but not all of mine have figured that out!
