Heat.. How to become colder when it is warm..
Find any organization with air conditioner like library store etc.
Find a canopy or shadow.
Water is the great source to become cooler. Merely swimming and sitting in the water helps a lot. If we have only bottled water, it is useful to soak clothes with that. Then put on wet clothes, they will serve as a coolant longer than if we just spray this water on a naked body. Clothes dry longer, especially those made of particular kinds of fabric like jeans e. g.
Underground and basement. Soil provides great insulation against high temperature.