Washington (CNN) -- Thousands of Girl Scouts, former members and supporters swarmed the National Mall on Saturday for the organization's 100-year celebration.
With the temperature reaching 90 degrees, 63 people were treated for heat-related incidents and 20 were transported to area hospitals, the District of Columbia Fire and EMS Twitter account said.
The heat prompted a steady stream of people at the event's four first aid tents all afternoon, Deputy Chief Kevin Byrne said, with many returning to the festivities after getting some water or ice. At one point, a fire truck was used to spray water on the crowd to cool them off.
Organizers declined to comment on any heat-related incidents.
The event, "Girl Scouts Rock the Mall", brought together scouts from around the world, organizers said, to watch performances, to participate in sing-alongs and other educational activities.
Juliette Gordon Low founded the Girl Scouts in 1912. She was posthumously awarded the Medal of Freedom by President Obama last month.