Since today is so hot out I figured this is something I can do out of the heat. Outside my window right now its 118, but my chickens are just fine. Before I list any other methods of keeping your chickens cool I want to list the life saver, The hessaire swamp cooler.
(note: swamp coolers work amazing in dry climates, so if you have High humidity it won't really help much)
[#1] Cooler, I cut a hole in the side of my coop, hardware clothed it up, slapped a diy reservoir on it and let her rip. My chickens are not even panting anymore. I have 2 coops and one does not have a run at the moment (almost finished with that) so my chicks are stuck in there all day. Its 8x16' and has massive ventilation but in this heat its just not enough, I can easily say that they would be dead now if I didn't buy this.
My adult chickens in the other coop would be laying and then run out minutes before the egg would pop out, laying it inevitably on the dirt. It was just way to hot. Now they lay even faster and enjoy it!
Some people might say this is a bit much for "just chickens" but I disagree, I worked very hard to build my coops and raise them from chicks, I love my chickens it would be stupid of me to let them die now. On the link I have a attached the cooler is of now 144$. If you stay home from eating out a few times you can already pay that. And if this thing last for years you just can't go wrong!
[#2] Cement mixing tubs! I'm sure many of you have heard of this method before, basically you have a tub or kiddy pool with about 1-2" water in it and put it in the run, Some people put brick in it on account of some chickens don't like to go into the water (the water soaks up through the bricks and cools them). I use to do that but found cleaning the bricks is kind of a mess lol. My chickens love going straight into the water. I 'dunked' there feet in there a few times when I first put it in and they soon got the hang of it. (My EE thinks she's a duck lol). you can also freeze a few bowls of water over night to add when its really hot.
[#3] Food! Frozen or cold corn, cold watermelon, frozen banana. ext.
I always keep a can of corn in my fridge for them, when I see its really hot out I go and dump a can of it in their baking tray, they love it! Watermelon is also a HUGE hit. when I see its on sale I buy about 3, stick them in the fridge and cut a few big rings and I give it to them. I place these big rings on either an old brownie tray that's just for them (look at 99cents store) or a plate. they eat it down to the green, it looks like a piece of paper when there done. I don't do the melon every day on account of the sugar, but it also keeps the very hydrated! The melons (big ones) last about a month.
[#4] ICE! A good way to keep there water cool is every night fill a bowl (plastic or metal) with water and add it to your freezer, then in the morning when you clean/refill there water, just add it in! This keeps it cold for quite some time.
[#5] Shade! I use lattice above my run to help keep the run as a whole cool but you can get a tarp, bed sheet or even a large cardboard box to give them shade. Maybe even an old table in the run,(I hang my feeder under one, keeps the rain of the food too). Shade is very important so also keep that in mind when you are placing and building your coop!
Well I hope some of these helped you in some way, The heat is always hard on them (and us!)Good luck with your chickens guys! And if you try out the cooler let me know!