I didn't realize how much I had acclimated to Houston's horrible summer weather (100+ degrees, 90+ percent humidity) until I went to Iowa in May and thought I was going to freeze. Fans are a must, even if you have AC--we keep our AC at 80 degrees or warmer but the ceiling fans make up the difference and are cheaper to run.
Tea is a diuretic so don't overdo it. I don't like cold water but water (at whatever temp you prefer) is the best. If you're sweating a lot, eat a little something salty, too. Mom and I went to a music festival once and the weather was so bad that we bought a bag of ice and took turns carrying it over our shoulders as we browsed. We were soaked but at least we were cold.
Bill D, you can still get window swamp coolers for VW Beetles (they have the regular ones that work when the car is moving, and fancy electric ones that power their own fans).