A 15-year-old high school football player died Tuesday from heat stroke after collapsing one day earlier following an offseason workout.

Coroner Stephen Boyle said Tyler L. Davis, a rising junior at Rockdale County High School, was taken to the county hospital before being transferred to Children's Health Care of Atlanta at Egleston, where he died.

Rockdale County is in the eastern suburbs of Atlanta.

James Ginn, spokesman for the Rockdale County Public Schools, said the district is investigating the death, and the school has canceled all football-related activities "until further notice."

Monday's workout session was voluntary because formal football practices do not begin statewide until Wednesday, Ginn said.

The football players lifted weights indoors for about an hour before heading out to the field to perform running and passing drills. Water was available to them throughout the training session, and they were outside with frequent breaks from about 5 p.m. to about 6:45 p.m., he said.

After practice, the players returned to the locker room, where the boy collapsed, Ginn said.

The school has brought in grief counselors to work with students, faculty and staff, he said.

Georgia, like much of the rest of the nation, has been sweltering under blistering heat.

Temperatures hovered in the mid-90s throughout the state Monday and Tuesday, with the heat index between 100 and 105 degrees.