But I find I'm doing things to cool off. I'm reverting back to habits I learned in Arizona, where I frequently lived in houses without A/C and once lived in a house with A/C I could only afford to cool to 85 degrees. So I offer you the benefit of my years of living in infernal temperatures in the hopes that some of these things may prove of use today.
First, don't cook in the house today, absolutely no oven use and preferably no boiling water. I find myself eating yogurt and cottage cheese (a nice sandwich can be made with it mixed with curry powder, celery, and cashews ... try putting it in a pita with some lettuce and tomatoes), and drinking iced tea. Today's probably the one day this year you can easily make sun tea, so if you've got a pickle jar, go for it. They say caffeine is dehydrating but I don't think it's that bad, and the cold water going in sure feels good.
I'll assume you already have a fan or two to help circulate the air.
Second, try taking lots of quick showers (coldish ones) if you're feeling overheated. Do it with some clothes on to make the feeling last longer.
Third, if tonight you find you can't sleep, stand in the shower WITH A SHEET WRAPPED AROUND YOU and go back to bed with the wet sheet. The evaporation will keep you cool. I did this three or four times a night in Phoenix the week it got up to 122 degrees and the AC in my rental house died. And the sheet got COMPLETELY DRY in between shower visits.
Other options for keeping cool ... hang out some place with AC (the movies are good, the one that came out about surfing might help even more). For some reason I think drinks with mint are extra cooling - mint italian sodas come to mind. I'd break down and go to a corporate coffee shop if it meant I'd get A/C. The library might be a good place to visit ... surely the fancy new one has a cooling system. And, of course, those fancy Sound Transit busses are air conditioned. Metro will be a drag today.
Finally ... try going to Lake Washington (Denny Blaine beach is the best place, I think) and resting in the shade, sporadically taking a dip in the water. Bring food, drinks, and a good book. You'll remember this as one of the most pleasant days of the summer if you do.