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 .
Girl Scouts celebrated heat 's 100th anniversary . They marched on National Mall in Washington . More than 100 people treated for heat - related causes .