Joining the August train with you!
I've only been to WDW in July. I've never actually used misting fans, Frogg Toggs, etc. The way I deal with the heat is by making sure I'm hydrated and cooling off. Every time you go into a new "land"/section of the park, look for at least one "cool-down attraction". For example, for Frontierland, it could be the Country Bear Jamboree, or Tomorrowland could be Carousel of Progress. Epcot, AK, and DHS has tons of movies. TLDR- my ideal of dealing with the heat is just by taking it easy and not cramming too much action into any given amount of time.