I added 1/4 mile to my distance to give a run of 3 1/4 miles. I had a great run. Even though I ran in the heat, I enjoyed the run. The temperature was 88 (F) when I left and 96 when I returned. Due to the increased distance, I think I'll take 4 bottles of water with me. The three bottles (8 oz each) is OK for 3 miles, but I'll need a 4th bottle as I increase up to 4 miles.
My wakeup heart rate was 56 and I felt pretty good during and after the run. I did take a few rest stops during the last mile -- no need to push myself in the summer heat, especially at my age. Spring and Fall are for pushing, and Summer and Winter are for surviving :)