All good suggestions so far, but I have a few to add:
Every 60/90/120 minutes (depending on need) go somewhere air conditioned and stay there until you completely stop sweating and are no longer hot AT ALL. Perodic total cool-down will go a much longer way than 5 minutes in an attraction.
Do a search on Amazon. com for cooling gear. They have everything from neck, head, and wrist coolers, entire cooling vests and even hats with built in fans.
Always have a pocket fan with you. You'll be more likely to carry a small fan than a big mister fan. They are indispensible for those times when you're in line, on the bus, or otherwise stuck somewhere where the air isn't moving. Evaporation is the body's air conditioning and it only works if there is air moving around you! The best fan I've found is no longer being made, but you may still find some around. It's made by Coleman and costs less than $3. They stopped making it because the blades are unshielded hard plastic. Yes it hurts if you get a finger caught in it, but the plastic moves a lot more air than foam blades. I found mine at Target about 2 weeks ago and bought all 5 they had.