Last night it rained pretty hard here, just at sunset, and cooled things down a bit. The upshot was that the morning was a few degrees cooler than usual, and it made a difference. There was also a nice breeze and lower humidity than I'm used to (it's usually around 90% when I go out).
I felt great today.
On an unrelated subject involving the word heat, I read a story this week about runners that pack heat. I guess I can understand that if you are a woman that runs at night, and moreso if you do a lot of trail running. But where would you put it? I cannot imagine any comfortable way of carrying a pistol while running.