We are in our second or third heat wave of the summer and I have to say none of them have really bothered me too much. I think the fact that we finally had an air conditioner built into the wall of our bedroom a few years ago has made all the difference for me.
The daylight hours are not so bad as long as I'm not busy around the house. I can read or work at my computer comfortably enough because there is nearly always a nice breeze going through my rooms with the open field across the street and lots of big windows all around. It's only those times where we have manual labor to do that make things uncomfortable. But the nights have always been the challenge. Those hot days with high humidity just really challenge me and I don't sleep well at all. There's something about sheets that feel wet and no way to cool off that just isn't very conducive to a good night of shut-eye, and lack of sleep certainly makes me grumpy.
So the a/c in the bedroom has made all the difference. I am sleeping well despite the heat and I'm getting lots of reading done during the daylight. All in all not a bad thing.