You can adapt to high temps. Drink water and consume enough electrolytes, and your body will learn to be more adept at keeping itself cool. Meanwhile, your brain will get used to high temps. The problem is that you are avoiding the heat, which means your body never adapts.

For heavy exercise, simply do it earlier or later in the day when temps are cooler. Warmer regions developed the siesta for a reason.

If you really hate it so much, move.