Speaking to those in hot climates, I believe open air coops are a way underrated feature/option. I think the first image that comes to mind when envisioning a chicken coop is a 4-sided solid structure, but in so many areas it doesn't need to be totally solid (or at least not solid at all times). I live in a mountainous desert area where summers are 100+ degrees and winters will get below freezing, so one wall of my coop (inside the fully secured run) was made removable to become an open air coop in the summer but can still be enclosed during harsh winters. When designing this coop I also thought 4 solid walls were needed, but when we move off this mountain my next coop will definitely be fully open air!
I love my open air coop!
Through a combination of careful design and good fortune, inside the coop is the coolest place in the yard on blistering hot days.