get a bucket top misting fan and put it on a 5 gallon bucket of cool water. it'll run a few hours. aim it at the roost in the evening. get a spare, longer (2ah or better) spare battery so you can run it several hours. you can connect it to a garden hose so it doesn't run dry.
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for daytime, you can also get a shallow tray of water and put clay bricks in it, so the bricks stick up about half way out of the water. the birds will sit or stand on the bricks to keep cool. also, turn the hose on and give them a puddle to stand in. you can also turn on the hose and spray the coop/run as often as possible. I used to aim the hose at the shade cloth for several minutes. you'll cool the air in the run and provide a cool puddle.
also, give them ice cubes or ice blocks in the water. I use half filled small cottage cheese containers that I freeze. the water needs to be cooled or they won't drink it if it's too warm.
you can go to the store and buy them a bag of ice and take it out of its bag and put it in the shade. it'll provide a cool spot for a couple/few hours.
I also fill 2-liter soda bottles half way and lay them down in the freezer. I put them outside in the shade for the birds to stand/sit next to to keep cool