maybe the answer goes without saying, but when its over 90F you do take the windshield off your motorcycle, yes?
I lived in Iowa for 4 years, in the summer it was so hot the only way we could sit outside was to sit in the shade of the garage, and put the garden hose in the gutter over our heads, spraying out a fine mist.
Ive wondered if putting something similar on a motorcycle would be viable for very hot days, a mist that sprays on your mesh jacket while you are riding, to keep your shirt damp in the windblast ?
When I first bought my 'liner, it was completely naked, and I wore only a full-face helmet. After the first year or so, I pretty much quit riding because the wind was beating the ever-lovin' stuffing outta me. I know "buffeting" isn't supposed to happen without a shield or fairing, but I'm telling you...I was getting a very violent, vibrating wind effect. You know the feeling where you think your eyeballs are gonna get shaken outta their sockets? Maybe it's my height, maybe it's the design of the 'liner, maybe it's my size 8 noggin, I don't know. But I didn't start riding much again until I got somewhat comfortable, and I didn't get comfortable until I put both a windshield and fork deflectors on. I still get plenty o' wind out there, for my taste.
I like the idea of a bike mister, but I'm not sure anything will help much in the dog days of summer. Over the course of July, August, and early September we'll probably catch 60 days of 100+. No amount of wind helps cool you off when it's that hot, in my experience. My guess is the air temps reach 130 or so 3, 4, 5 feet above the asphalt. I usually just wimp out till it eases up.