Sleep during the day, awake during the night. (One of the advantages of being an educator - summer break!)
Wear less. (In the privacy of your home, I mean.) Move very little. Get that personal fan pointed right at your face and neck. Stay put and consume resources.
Visit somewhere that has awesome A/C. Oh, look, a Starbucks! (For you, Arwen, Tim Horton's.) Yes, I'd like a bottle of water, please. And I'll be camping in that corner there for the next three hours with my laptop/kindle/book/cross-stitch.
Spray bottle with ice water in it. Give your face a blast every couple of minutes. (May not be as effective in areas with high humidity.)
Make and eat popsicles. Om nom nom nom.