The Mall has plenty of tourists taking in the sights, but there are also other folks weaving in and out of those crowds - bikers and joggers, who are all sweating in the extreme heat.
After all, how can you not be when the heat index reaches 101?
"You don't need to be a doctor to use common sense," says Dr. Gigi El-Bayoumi, who explains that mixing extreme heat and exercise causes the body's core temperature to go up.
This doesn't seem to bother runner Andy Loomis, who says: "When I run in the middle of the day, I have a more productive afternoon than if I'm sitting at my desk, eating my lunch. I think it's crazy to be slouching at your desk all day long."
The doctor says heat is not the only thing people have to worry about - the air quality is another factor: "You're sweating. You really can't keep up."
30-year-old Jonathan Wachtel is another runner who exercised this morning and was back again for round two. "It's a bit warmer than usual, and it's a little humid," he says. "It's all about hydration and good nutrition."
Dr. El-Bayoumi says to pay attention to your body. It is recommended to exercise at sunrise or sunset.