While you will here more CMs state shoes must be worn, there are some that will also tell you that shirts must be worn. Mostly they do not bother and let little boys go without shirts, but I have seen them do it. They will almost always tell men they need to wear shirts. The day it was 106 I think the most crowded area of dca were the water areas. They had CMs at all 3 of them watching for people with no shoes.
The best area for adults to cool down is the farm area because they have a mister on top that goes around, you can stand where you get misted, but not drenched. It was definately nice that day to be standing there, though it was hard to find a spot because i wasn't the only one looking to cool down.