My wakeup heart rate was 54 this morning. I had a good 7 hours of sleep, and I felt great when I began the day. I didn't go out running until about 1 pm, and by then the shade temperature was 92 (F). I drank 3 cups of water during the run, and on the way back, I stopped several times in shady spots and rested for a couple of minutes. As I've said before, in the Summer and Winter I run to survive, and in the Fall and Spring I run for performance. In all four seasons, I run for enjoyment. I went south 1.75 miles and then came back. I think that for my next run, I'll drive to the pavilion at 108th South and run to the construction at 114 South and check it out.
I really can't say for sure, but I'm hoping my enjoyment of the run today means I'm adjusting to the heat.