Since I gave up air conditioning over a year ago I do a lot better with the heat, counter-intuitive I know, but true!
I used to be one of those people who ran from air conditioned island (vehicle) to air conditioned island (store) and only braved the heat (outdoors) when I had no choice. Summer was pretty miserable when it got really hot. Now that I'm not in the air conditioning all the time I don't really notice the heat until it gets north of about 90F, and I can stand more than that. Now stepping into air conditioning at a store is refreshing instead of necessary. I know it sounds horrible, but I recommend it, you really do get used to it after a while.