Tips to beat the heat in the summer?

Well here it is again. Highs above 100, temps maybe beneath 90 by dark if we're lucky. I love to fly, buuuuttt..... every year around this time, I stop flying so much because it's basically: sweaty preflight (depending on which airport I fly a Skyhawk out of, it may be done entirely without shade), sweat pouring down my face during taxi, some relief during the flight, maybe if it's long enough for me to climb 8000'. Then, of course, pack everything up in the heat too. My wife doesn't enjoy flying with me in the summer due to the heat, and honestly I don't either.

What tips do you all have to beat the heat with summer flying in a Skyhawk? Note that I rent from flying clubs (one of which has a hangar so I can at least preflight in the shade, but the other is at one of those airports where they pull the plane out onto the ramp first thing in the AM and it's out all day), so things like "find a better hangar" isn't within my power to do.

Early mornings aren't all that workable for me schedule-wise most of the time either, I'm afraid.