Many people spent a significant part of Memorial Day outdoors on what was the first 90 degree day of the year.
The high temperature proved to be downright dangerous for more than a dozen people who were hospitalized because of the intense heat.
Shirina Cannon, of Baltimore, said, "Really hot today, pouring sweat today. It was really bad. "
Fire and EMS crews responded to more than a dozen heat-related calls, including one at 21st and E Streets after several youngsters from a Tennessee marching band fell ill.
D.C. resident Steve Glazier said, "The humidity's bad. As they say, it's not the heat, it's the humidity."
While emergency crews scrambled from call to call, facilities like the National Zoo provided misting showers to help guests from overheating.
"It's pretty cool. It's like wetting me, so I don't get really hot," zoo visitor Brandon Moreno remarked.
With temperatures in the 90s, even a casual game of volley ball required lots of fluids.
D.C. resident Jean-Claude Lelan said, "It's very dangerous. I'm a chef in a kitchen, so you know what I do? Drink lots of liquids and put my face under cold water."
Beth Joffrion, of D.C., added, "...it's not even summer yet,"