My wakeup HR was 51 and I felt fine during my stretches. I drank 1/2 cup water when I first got up and 1 cup after I ate a banana and just before I left for the Jordan River Parkway. I left an hour later that I should have and thus ended the run in 90+ (F) shade temperatures. The direct-sun temperature would have been about 120 degrees. I think I'm adjusting to the heat. I only took one walking break that wasn't at a mile marker, and that break was to eat a granola bar and drink some water. I felt fine during the run and (so far) feel fine afterwards.