Arizona State hockey player in coma after heat-related collapse during team workout

Sun Devils defenseman Matthew Maycon collapsed during the first day of fall-semester workouts on Aug. 20 and was later placed in a coma. First responders treated him for a heat-related illness and he was taken to a local hospital before being transferred to the Barrow Neurological Institute in Phoenix, where he remains under intensive care.

The temperature at the time of the workout was reported at 87-89 °F. According to Maycon’s attorney, Robert Carey, the session was led by former Green Beret Tim Ziesel, who allegedly directed “grueling” drills and discouraged complaints, providing water only to exercise leaders. Carey said Maycon showed signs of distress, was disoriented and struggled before collapsing.

Ziesel disputed the description, stating he left the workout before Maycon fell and that the routine was comparable to a high-school football conditioning program, not a military-style drill. Ziesel’s attorney added that the head coach, assistant coaches and medical staff were present throughout and expressed devastation over the incident, calling for an objective investigation.

Maycon, a 2023 sixth-round NHL draft pick of the St. Louis Blues, transferred to Arizona State from Clarkson University after four seasons with the Ottawa 67s of the OHL. The university said it is reviewing all aspects of the workout as the investigation continues.

Carey told the Arizona Republic that Maycon has “zero chance of recovery” and that his family doubts the school’s handling of the inquiry, accusing officials of downplaying the intensity of the session.