Experts warn heatstroke deaths in sport are ‘tragic but avoidable’ as global temperatures rise

The tragic death of Fijian rugby player Saimoni Vunilagi has reignited urgent debates regarding athlete safety during extreme heatwaves. Vunilagi, 26, passed away on August 6 after collapsing during a training session with Japanese club Kyuden Voltex in Fukuoka. The club stated that he exhibited symptoms consistent with severe heatstroke, despite medical interventions. At the time of the incident, temperatures had reached 35C with humidity exceeding 75%, continuing a streak of daily highs between 32C and 37C.

This incident follows a pattern of heat-related emergencies across global sports in 2026. In tennis, Jakub Mensik and Ekaterina Alexandrova collapsed during matches exceeding 30C, while eight runners required hospitalization at a South Korean marathon where temperatures hit 29C. Cyclists Tadej Pogacar and Matthew Brennan also publicly criticized the dangerous conditions during the Tour de France and Vuelta a Espana, respectively. Additionally, FIFA introduced mandatory hydration breaks during this summer’s World Cup to protect player welfare.

Dr. Madeleine Orr, an assistant professor of sport ecology at the University of Toronto, emphasized that heat illness events are increasing in rugby and other disciplines. She cautioned against the misconception that athletes can simply endure heat as they did in the past, noting that modern heatwaves are more intense because local temperature baselines have shifted. “We have seen an increase in the number of heat illness events… People assume we’ve seen such extreme heat before,” Orr said. “That’s not necessarily true.”

While sports such as tennis, athletics, and cycling utilize the Wet Bulb Globe Temperature (WBGT) index to monitor heat stress, experts argue that protocols remain inconsistent. Orr compared the need for standardized heat safety rules to existing lightning policies, which typically mandate a 30-minute pause when storms are nearby. She called for a universal approach where specific thresholds automatically trigger suspensions or postponements, removing subjective decision-making from coaches and organizers.

Christian Day, general secretary of the Rugby Players’ Association, highlighted the cultural barrier preventing athletes from prioritizing their health. He noted that coaches often view heat regulation as a hindrance and that players fear being perceived as weak if they report feeling unwell. “Players need protecting from themselves sometimes,” Day explained. Although World Rugby updated its guidelines in 2025 to include a heat stress index ranging from 0 to 250, Day argued that because athletes train far more than they compete, central governance is needed to regulate training loads and durations during extreme weather.

Heatstroke is a medical emergency where the body’s cooling mechanisms fail, potentially leading to organ damage and death within an hour. Symptoms include confusion, nausea, dizziness, and slurred speech. Dr. Orr stressed that fitness does not confer immunity to heatstroke; in fact, larger body masses generate more heat and require more energy to move, increasing vulnerability. She pointed out that preventable deaths send negative signals to grassroots levels, making it critical for elite sports to set exemplary safety standards for future generations.