Ok, So its like 92 deg and 85% humidity. how do you guys not sweat your butts off?
Have a very large butt.

I was just wondering if you all had any ideas of keeping cooler, or not sweating your kilts out.
Yeah; in the heat, cotton drawers are more comfortable than reggie.
A rub of something like Secret invisible antiperspirant between the thighs helps a little.
If you must wear hose, get really cheap thin ones. I've got some from Sport Kilts that are (relatively) quite comfortable yet presentable.
Avoid having to wear a jacket if at all possible. As a piper, I can't always do that, so I at least minimize the amount of time I wear it to only when I'm being paid to.
I find so-called Jacobite shirts to be a lot hotter than a short-sleeve Oxford, tropical uniform shirt, or polo shirt.
Situational awareness; always know where the shade is. Go stand in it; it's amazing how much cooler you'll feel.
Hydrate, hydrate, hydrate.
Always at least air out/air dry your kilts before hanging them back up in the closet, perhaps folding a dryer sheet into it when you clip it into the hanger.