Forget about the wet underwear and clothes...
Whenever I see a kid dancing in the fountains there's one thing I'm thinking of....

W E T S N E A K E R S !!!!!!!
When I was a kid my mother gave two #@$% about my appearance/feelings/etc. I know it's fun to have fun getting all wet, but after an hour or two walking around in wet sneakers, that is pure torture.
Sure, for a few minutes they're all nice and cool, but then the humidity sneaks in and then your feet get hot and clammy, and then the blisters start erupting all over your foot in places you've never got blisters before!
My husband had his kneecap operated on six months prior to one of our trips (major work, not replacement, though) and when we went to Seaworld he went on that wonderful Atlantis ride and got soaked. We were only there a few hours before that.
After the ride, about an hour, he was MISERABLE because his feet were so wet and he did not bring his water shoes to change into. It also affected his knee and he was limping and felt horrible. So we had to leave. At least the kids got to feed the dolphins!
So parents, please, if you're gonna let your kid play in the fountains, bring an extra set of sneaks or just take their sneakers off and let them go barefoot!
Everyone knows it takes forever and a day to get sneakers to dry and most people only bring one set of sneakers. Don't do that to your kid. Everyone wants to be comfortable. It will make your time in the parks more enjoyable, and your kids won't walk around complaining - and no blisters....