Hillsborough County (Fla.) Public Schools have reportedly halted all summer athletic activities after the sudden death of an incoming freshman who was participating in conditioning drills with the football team.

The Tampa Bay Times reports that 14-year-old Hezekiah B. Walters collapsed on the football field of Middleton (Fla.) High School after working out with the football team for about 30 to 40 minutes. The district told the Times that coaches immediately called 911, and paramedics were dispatched to the scene. Walters was transported to St. Joseph’s Hospital and later pronounced dead.

Police said that the team workout included weight lifting and sprints, and included water breaks.

Official high school football practices in Florida don’t start until July 29, but unofficial conditioning workouts do take place. Those conditioning sessions must be supervised by an adult, and take place on school grounds.

The specific cause of Walters’ death is now under investigation by the county medical examiner, however, as the Times points out, deaths caused by heat stroke are a notable concern in high school football. The Florida High School Athletic Association’s heat acclimatization policy requires coaches to review the heat illness prevention course provided by the National Federation of State High School Association.

Since the death, the district has mandated a full review of safety procedures before offseason conditioning work can resume. Coaches will be required to review safety procedures, and school staff will check each student’s record to make sure they are eligible to participate in athletics. Every principal in the district will be responsible for informing the district that those steps have been completed.

Jason Scott is Online Managing Editor of Athletic Business.