Most of those who suffered heat-related problems during the Oklahoma Twister Relief Concert in Norman were treated by medics at the University of Oklahoma stadium, but 170 required more treatment and 21 were taken to hospitals, Norman Regional Health System spokesman Kelly Wells told NBC News.
More than 60,000 people attended the concert to see stars such as Toby Keith, an Oklahoma native; Garth Brooks, Sammy Hagar, Trisha Yearwood, and Willie Nelson perform, The Oklahoman, Oklahoma City, reported.
Proceeds from the sold-out event are to go to victims of tornadoes that hit Oklahoma in May, killing scores of people and destroying homes, businesses and schools.
Keith, who organized the show, said a lot of work went into pulling it off.
"It was like herding cats," Keith told reporters Saturday afternoon. "You've got a lot of managers, you've got a lot of artists, you've got a lot of folks ... that you've got to deal with to make everybody's happy. So we've had to go through all that. But everybody's here for the right reasons, and it's gonna be a big show for Oklahoma ... and it's gonna take care of some people for a long time."