Heck, it's still hot here in October. I was hunting in shorts and a T shirt with my Bug Tamer and snake boots until late October. You do what you have to do to hunt. Deer move in late evenings and early AM, throw out the lunar tables, they don't mean a thing. Deer live in the elements every day, never seen one in an air conditioned field, never killed one in the air conditioning either. Though I do know of a rich landowner that had a air/heat conditioned stand. Had a garage and elevator too, his seat was a recliner, camo of course.
You just suck it up, take plenty of water and go sweat.