I've got a cheapo box fan that does pretty good at keeping me comfortable when i'm working out there. I have a window shaker AC unit that I need to mount, but might be looking more at a swamper setup. My dad's neighbor has one in his garage and it works pretty good. Only concern is the humidity making everything rusty...It has been brutal. I had some time to work on it Saturday afternoon, but it was 110° in the garage, that wasn't happening.
Even this morning, I got a couple hours in on it before work, started at 5am, opened the garage door and it got "down" to 88°
Normally I'd just leave it until the weather cools off, but I really want it done for the fall driving weather.