Little bodies don't work like older bodies. It was 115 last Monday and I ran 10k. I like the heat so I was good. But I'm conscious of my body. When I ran 2 days later, the same route, and it was like 102 my heart rate was too high for no apparent reason. Couldn't stabilize so after 30 mins I called it quits. Waited for the heat to drop and ran at night.