I'm totally unconvinced by this claim eating or drinking hot things in hot weather cools one down. I sweat more than enough in the sun as it is. Encouraging more simply isn't going to help, and since I would be doing so by making myself even hotter than I had been, well the logic just doesn't follow.
Im unsure I've ever met a normal person, but I suspect in the hot weather they'd prefer cold foods to hot. Fruit, ice creams, chilled drinks. Potato salad, maybe with cold slices of ham & sweetcorn ? Ploughman's lunch with lots of pickle ? Barrel of cold beer ? Sandwiches. Cold buffet stuff. Or maybe folk don't feel much like eating in this hot weather anyway.