An investigation into the death of Baltimore Orioles pitcher Steve Belcher has revealed that he was taking an over-the-counter weight loss supplement that has been linked to heatstroke at the time of his death. Belcher died on Monday after being hospitalized the previous day for heatstroke following Orioles workouts. The major leaguer’s temperature was 106° when he reached the hospital and later rose to 108°.

According to the medical examiner who performed Belcher’s autopsy, the pitcher was taking the supplement Xenadrine RFA-1 in order to lose weight. Xenadrine contains ephedra, which raises the body’s temperature and increases the rate at which fat is burned. Because it also constricts blood vessels, ephedra makes it harder for heat to be released from the body.

Ephedra supplements were banned by the National Football League following the death of Minnesota Vikings offensive lineman Corey Stringer from heatstroke a year and a half ago. Ephedra has also been banned by the National Collegiate Athletic Association and the International Olympic Committee.