If you're not used to the HUMID heat, I suggest you do all that you can to avoid becoming overheated and dehydrated. The hot humidity can really get to people if they're not used to it or prepare for it. Kids are especially susceptible to the heat. With that said, this is what we did:
1. We brought one frozen bottle water per person and put it in a collapsible cooler that I bought at the dollar store. (There were only 4 of us.) We also brought 1 or 2 not frozen so we could start drinking those right away.
2. We had a water mister/fan combo we bought at
Walmart for the 2 kiddos. The kiddos loved those.
3. We wore neck coolers throughout the day. Those were the best things to combat the heat!! A couple of ways we used them: (a) We put them in the fridge the night before and put them in the collapsible cooler until we needed them. (b) We put them in the freezer, but had them in a plastic bag until we needed them. I liked (b) better because while they were in the bag and we walked around the parks, the neck coolers were thawing out. Now when ice thaws, the outsides thaw out first while the insides thaw last, right? Well, the neck coolers thawed the same way; so, by the time we needed them, the outsides of the neck cooler were still very cold while the inner core still felt frozen, keeping the whole neck cooler, cooler longer. Now I wouldn't put a frozen neck cooler on your skin, but only the inner core felt frozen while the outer core was cool and comfortable, if that makes sense. Also, by lunchtime, we usually sat inside so we felt comfortable enough to take off our neck coolers. We just put them into our collapsible cooler, poured ice over them (we got an extra cup of ice during lunch), and by the time we were done with lunch, the neck coolers were recharged and felt oh-so-good again. We were ready for the heat!
4. Wear deodorant.

Nuff said.
-Dee