Spectator medicine at an international mega sports event: Rugby World Cup 2019 in Japan.

Preparation and provision of appropriate medical service for spectators is a key factor for mass-gathering events. During RWC 2019, the majority (91.5%) of patients who sought medical attention did so for minor complaints, which were easily assessed and managed. On the other hand, a higher WBGT situation contributes significantly to an increased PPR (< 21 versus > 25, 2.04 versus 4.27, p = 0.04). Careful medical preparation, management, and development of public education programs for higher WBGT situations will be required in the future for similar international mega sports events.