My coop is a wood frame with small chicken wire, a tin roof. I have their roost in a 3-sided plywood "hutch" to block drafts. If I had to do it over again, I would make the hutch in such a way that the back could be easily removed for summer, and replaced in the winter. In the fall, I cover all the sides of the coop with plastic sheeting and remove it when it warms up in the spring. The chicken wire ceiling and tin roof allow for ventilation.
The summer heat is what you will really need to address. They will need shade and good airflow. We have hot, dry summers here, and I have shade for the coop, but on one side, I drape shade cloth to keep things cooler. Depending on how much shade you have, you may even want to use misters in the summer.
Lynn