I always wear a bandana when tourusting about in hot weather. Make it wet from a water bottle and put it on my neck for a bit of instant continuous cooling. Put it on the head, spreading around the forehead for even more cooling. Put it on my wrist and then occasionally wipe the forehead for occasional / no cooling.

Another “trick” is cardiovascular health. I was miserable in heat for some time but thing got a lot better after I picked up cycling - 32 c humid heat produced no discomfort (apart from sweat).