What about a swamp cooler? The hottest camping I did was probably at Ft. Polk, La in July and August, but then I got use to it. Another hot spot was Ft. Sam Houston, Tx, and yes even worse would be Ft. Hood,Tx. I was getting a small window unit that is actually a protable, it cools about a 12X12 room, but as the temp gets at the 100 mark, I'm sure I would want to put it overhead and sit in front of it.
I'm aware of sailors using swamp coolers or water coolers dripping water over fins and a fan.