"We were made to sweat. The sweat is what keeps you cool," Jose Perez said.
But sweat has to evaporate to cool, and that's not possible in high humidity. A point proven by Scott Rapoport's soaked shirt.
"I know you're a doctor and I know what you want to tell me, but I think as long as I have enough of this and drink water beforehand I'm okay," he said.
If you are really sweating, sip on sports drinks or use electrolyte tablets. They turn your water into a sports drink.
For any hot weather run, hydrate beforehand and bring water with you.
"Constantly take a sip every mile, every 10 to 15 minutes," Mack Exilus, assistant manager at New York Running Company, said.
Exilus recommends loose clothing made of moisture wicking fabric.
"They're lightweight very synthetic very breathable so it keeps you cool," he said.
Even better, don't wear a shirt.
Jose Perez runs 3 or 4 miles a day.
"Your whole system gets into a balance with breathing and heart rate are working together," Perez said.
It's true that over time your body can get used to the heat.
It's called heat acclimatization training. Your body becomes physiologically more efficient and tolerant in the heat. But that takes days of training, and even for conditioned athletes, heat exhaustion can sneak up on you.
As a runner and performance specialist at the Hospital for Special Surgery, Jamie Osmak says know when to when to call it quits.
"If you're feeling faint or dizzy, if I'm really, really sweating and feel like I'm overheating I stop and go home," Osmak said.
My advice is run only in the morning or the late evening, or even better run inside.