Aug. 5: At Hopewell High School in central Virginia, 10th grader Javion Taylor, 15, collapsed during a drill session with the junior varsity team and died in an afternoon practice.

In addition to Noble and Taylor, news accounts referred to the possibility of heat in the deaths of Semaj Wilkins, 14, of New Brockton High School in Alabama, and Ovet Gomez Regalado, 15, of ...