Live without air conditioning. Your ancestors did.

Sit under a tree.

I’d you get fatigued don’t just rinse off in a cold shower, immerse in cold water. Whole torso.

If you can’t do that lie on the floor and put ice packs on your armpits. It will cool your core.

I always hated a shared swimming pool in hot weather. When I was a kid we swam in cold water but today’s soft people have to warm their swimming pools. Tepid water is not refreshing.