For cheap hot weather gear, look for a nylon shooting vest, the kind that has the big "game pocket" in the back. When the temps get up around a ton, you get a couple of big ziplock bags, fill 'em with ice, and stick them back in that game pocket and snuggle 'em up right over your kidneys.
Thanks. Great idea. Don't get much hot weather here at the Central Left Coast. I'm lookin' forward to movin' inland. Gimme sun. Gimme heat. I was gonna use Lizard as my handle, but "Liz" just didn't fit.