It was so hot and muggy at LCX that my wifes T800's were fogging.
I was wearing WileyX SG's, which are notorious for fogging.
Luckly a teamate had a bottle of a product called "Seadrops"
He used it succesfully used at Red Storm 2 which I heard was super humid due it raining.
Worked flawlessly!
Sports Chalet carries it. Best I've ever used. Only a few bucks a bottle, buy the red one.
Make sure to follow directions to the letter.