I live in Iowa also. It was crazy hot yesterday for around here. Two of the bay areas in my scrap shop are air-conditioned and I have doors between them and the warehouse area. It is not too difficult to cool; them as they are insulated and have lower ceilings installed. It does cost money to cool it, but it is also tolerable most of the time without running the A/C. My shop is positioned as such that the front is not in direct sunlight and it seems there is usually a nice breeze.