Here in Thailand, it is always hot and the only precaution I take is to store my CYA glue in the refrigerator. If not, the bottle is solid in 1-2 days as the humidity and heat reach the liquid and start it curing. Everything else is stored in my shop, which reaches a maximum of about 90 degrees F on the hottest days. (Much hotter outside but it is brick and protected from the sun so the temperature is moderated inside.) Epoxies, paints, and even MonoKote seem to not be affected too much by the heat. If your shop has windows, make sure the sun can't hit any plastics or stored liquids.

One thing you might do is check the power consumption of window or small air conditioning units. Our bedroom has a 15,000 BTU AC that keeps it frigid, and it only draws 1000 watts. With our local utility prices, that only amounts to about 12 cents an hour if it runs all the time, but normally it is only on about 20% of the time, so about 3 cents an hour. I don't think a small window AC running in your shop when you are working there would set you back much, and it would do a lot to make you comfortable.