I feel for you and am deathly afraid of the same fate for our 15 week olds. We live in Washington state and are facing a historic "heat dome" event with 8+ days of triple digit temps - 114 is predicted midweek. Our 4'x4' coop and 4'x15' run are in our garden with no natural shade. On both sides we have shade blinds and fabric, and misters, as well as fans at both ends. Today we put up pop-up tents over the top to hopefully keep direct sun off of the roof and walls because it doesn't cool down at night. I have an extra large pan that I keep frozen water bottles and cold bricks in that they drink from and can stand on/in. They have two drinkers that I replenish with ice every couple of hours or so. They've always turned up their beaks at frozen treats but this week they are devouring them. The coop holds heat at night so I've been putting a small rechargeable tent fan in front of frozen water bottles in a corner and it seems to blow cool air. Today I broke down and bought one of those mini swamp coolers to see if will bring them any relief at all in their coop at night. They dig holes in the bottom of the run to cool off, but we also leave the door to their run open and when they get too hot, they look for a cooler place. Unfortunately that's the flower beds behind our house, but sacrificing our flowers for their comfort is worth it. They are so uncomfortable and I feel horrible that I can't do more to help them.
Does anyone bring their chickens indoors when it's 114 degrees outside?