Several years ago we had a hot, dry summer much like this one, although this one is hotter. In one day that summer I lost 5 chickens to the heat, including a broody hen who refused to leave her eggs in the hot building.
After that day I made a few changes and until this week I hadn't lost another chicken to the heat. I hope I won't lose any more this year.
The first thing I did that year was put a screen door on the chicken coop. It doesn't fit correctly, and is taller than the coop is, so it isn't pretty, but I think it's the most effective thing I did. There is now the screen door on the east side, and the chicken-size door on the west side so that there is a cross-breeze. There is open space where the rafters meet the walls on all four sides. In winter I replace the screen door with the solid wood door.
The two windows are inoperable so they don't help. The window on the south side is a large picture window that is great in the winter but not in the summer. I hung a black tarp on the inside of the window to help bring down the interior temperature. Since then the tarp has fallen apart and isn't in use this year.
I also spread an old comforter over the top of the chicken run on the west side of the coop that summer. This gave the hens an open-air "covered patio". This year I used some shade fabric, but it only lasted a month before the wind shredded it. I've been hunting at thrift stores to find another comforter, but couldn't wait any longer. So temporarily I am using an old comforter that I keep around to put on the floor of the back seat of the truck when I transport goats. It's twin size and not really big enough, but is better than nothing. I'll keep looking for a larger one.
I even gave the hens a wading pool that year, and have put it in the run again this year. We have a shallow plastic tray that had been under a rabbit cage; I put it in the chicken run and daily fill it with water. The hens enjoy standing in their pool to cool off. (See those pesky white-and-black cockerels still in the coop? I've been moving them one at a time as I can catch them, so there are a couple left. And OH, one might be a pullet after all!)
When hubby fills the troughs in the evening, he sends a shower of water from the hose into the chicken run. He says the hens come running out to stand in the "rain".
We've had the hottest June and the hottest July in Oklahoma history. I'm guessing we'll have the hottest summer on record when all is said and done. The hottest day ever recorded is 113°, and the weather forecasters are predicting that we will break that record too - and it might be TODAY!
If you have any other suggestions for keeping chickens or other animals cool in summer, please leave a comment below.