Kids these days are so privileged. Most of them had been to a theme park of some kind.
When in theme parks, remember to drink plenty of water. If someone in your group does get dehydrated, get to the First Aid Station. Each Disney theme park has one. Wearing the right shoes is necessary and that reminds me that I should get a pair of Zamberlan 230 crosser soon for my trip.
This is the best tip, which is why Iím saving it for the last. If you have tots, let them set the pace. Kids get cranky easily in the heat. This is more so considering that while you are looking at castles, they are in a hot stroller with nothing interesting at eye level. So if the kids are tired, head to somewhere with air-conditioning, have a break in a restaurant, or do anything that allows everyone to cool down.