Good thread here ~ and thanks to everyone for sharing your local weather conditions and hot-weather chicken solutions.
Here in Mid-TN we are getting to the 95-100 mark this week.
According the Gail Damerow Chicken Health Handbook, chickens begin to pant at 85 F (which I have found true with mine), and there is danger of death from overheating past 104 F. However, Mahonri and a couple of others in the Southwest indicate their hens are doing fine up to 112. Good to know.
Although my girls have a 40% tinted roof on their weekday run, this week we covered part of the roof in a Cabela's camo hunting gear cover, and the rest (including coop roof) with old military tarps for some extra shade. When I went home at lunch to check, the coop internal temp was 94 ~ but after sliding two 1-gal. frozen juice bottles in the coop near the nest boxes, the temp quickly started dropping. It was pretty comfy near the ground of the run where the chooks were; the extra shade is working.
I also put out a heavy Pyrex baking dish full of ice, and a flatter-shaped frozen juice bottle in the run. The girls play around with the tray-ice as it melts, and then they have a nice cool extra water source to play in until I get home (when I left, my kooky girl was walking back and forth over the tray of ice). Sometimes they stand or perch on the frozen bottle.
If I know there will be no rain, I put out a huge fan to blow at an angle so the hens can stand near it if they want, but step away from it if they don't like it.
Iced down fruit and cucumbers are also a nice treat when it's hot. A good, deep crater of cool, loose dirt is appreciated, too!
Hope everyone stays cool as we get into the really hot days of late summer.