I followed my 20km run on Sunday with a good 10.5k run today. Since it was a holiday, I decided to take it easy (which means more sleep!) and started at 8.30am. As expected it was going to be quite sunny and hot, but I wanted to see if my ability to bear the heat had improved and I was pleasantly surprised to find that I did quite well.
I did the run in a little over an hour. I managed the heat quite well, thanks primarily to the regular runs and the energy drink. My legs were not at their best but still managed a good time, though my left calf is a little strained after the run.
The biggest benefit of running in the sun, is the improved endurance (and maybe even immunity) to take on the sun & heat, whenever I go out the artificial comfort of indoors. Plus it also helps manage change in weather better, be it shuffling from air conditioned climate to extreme heat and humidity outdoors, or natural change in weather (esp. sudden drop in temperature). So, if I keep myself well hydrated and have my sun shades, there is absolutely no chance of a heat stroke.