I also find that making sure they have plenty of dust bathing area helps a lot. The ground, dirt, sand etc stays cool and helps them stay cool as well.
This was my haul from my local Tractor Supply. I'm in the process of building another coop. I plan to go back to get more there and at my local Lowes as well.
I decided to do this when I saw the ridiculous lumber prices now. I simply can't afford them for what I want to build. It does require...