We have had several five-or-more-day heat waves where I live as well, and this is our first year for chickens. They’ve done OK, and we did what everyone else suggested here — frozen watermelon, tops of strawberries, cut up bruised peaches, the shallow water bath, although they didn’t really get the idea of that. The last thing we did was purchase this bucket mister, which sits on top of a bucket of cold water or even a bucket of ice without power or a hose. Our coop is too far away from our house to do either of those. The battery that fits most power tools runs for about three hours:
https://www.homedepot.com/p/RYOBI-O...jJEDQSSYV7tw9OLI_cRoC8HgQAvD_BwE&gclsrc=aw.ds