I'm also in Central Texas. I have only 5 hens, now going on 7 years old. Relatively small coop and run, but totally enclosed. I have shadecloth on all sides of the run, and 2 box fans at right angles for the run. Last few days, with 100° Temps, I hose down the shadeclth 3-4x a day. I have small thermometers in the coop and run, and the hosing takes the temp down about 5°. The ambient temperature feels much more comfortable.
I have a large dust bath with sand, food greade diatomaceous earth and coop refresher. I have 4 footbaths--14" plastic trays from Amazon, actually planter liners. I bought 6" concrete papers to put inside the footbaths. My hens LOVE standing in these. They feel safe because they're so shallow. I bring the hose in to clean them every day. Wish I knew how to post a photo... I make a gallon of electrolyte water at a time (many recipes online), and keep it in refrigerator. I use a small hanging waterer, with 6 or 7 ice cubes and use only a few inches of this water. I wash and change it every day. When it gets hot, mid afternoon, I use a pie plate, barely cover it with their organic feed, add 3 ice cubes, and cover the pellets with electrolyte water. Sprinkle organic cayenne or garlic powder on top. They clean the bowl by bedtime. I freeze watermelon in small slices, and give them a few as an evening refresh before bed.
The coop has Gans in 3 of the 4 windows, and I have a 6"fan hanging in front of the preferred nesting box, which seems to help, because I don't see as much open-mouth breathing since I began this. I also have a silver car window shade over the outside of the coop where the nesting boxes are, and I spray this and the roof when I spray the side shadecloths.
My friend accuses me of micromanaging my chickens, lol. I don't care. I'm an animal rescuer. And do the same with my rescued cats and pittie. I'm an ethical vegan, and my chickens are pets. Except for giving an occasional egg to my pets, or cooking them to feed back to the hens, I give the eggs to my neighbors. So my situation may be different than most of you nice people here. But I've never lost a hen to heatstroke. A neighbor does free-range, and lost 7 of his 9 chickens to heatstroke. This breaks my heart. He just doesn't set up any shade or fans.
