As the largest FIFA World Cup in history kicks off across North America, the most menacing wild card for the 48 competing countries might be the stifling summer heat. Over the monthlong marathon leading up to the July 19 championship match in New Jersey, relentlessly high temperatures and humidity will put millions of soccer enthusiasts at risk.
While elite athletes endure at least 90 minutes on the pitch, spectators, match officials, and workers in many of the 16 stadiums across the U.S., Mexico, and Canada could be highly vulnerable to heat related illness and exacerbation of chronic health conditions.
Early Heat Exposure at World Cup Training Bases
Teams from Norway, Scotland, and Germany have gotten a taste of the "wet blanket" extreme heat at their base camps and training sites in Greensboro, Charlotte, and Winston Salem.
When Norway opened its practice to the public on June 10 at the UNC Greensboro soccer stadium, temperatures climbed close to 90 degrees Fahrenheit that afternoon. The next day, the National Weather Service issued a heat advisory, which is based primarily on the heat index, or the "feels like" temperature that takes humidity into account too.
Ashley Ward, director of the Heat Policy Innovation Hub at the Duke University Nicholas Institute for Energy, Environment & Sustainability has advocated for years for use of the wet bulb globe temperature, developed and used by the military for decades, as the standard measure for public heat safety.
It incorporates not only air temperature and humidity, but also wind speed and solar radiation, and because of that it gives us a better predictor of when conditions outside are particularly dangerous to humans. It's not just about getting hot. It's also about how humid it is. Is the wind blowing or not blowing? Are there clouds in the sky, not in the sky? Are we standing on asphalt? Or are we standing on grass, and so forth?
Ward said there is a lot more than the number on an analog thermometer and humidity level to consider when thinking about heat safety.
Is FIFA's Heat Policy Adequate?
FIFA, the worldwide governing organization for soccer, uses wet bulb globe temperature to set parameters for postponing matches. Delays are considered when the wet bulb temperature hits 32 degrees Celsius, or 89.6 degrees Fahrenheit, a threshold that has caused controversy among some scientists and players' unions.
In an open letter to FIFA on May 13, 21 doctors, climate researchers, and scientists from universities and research institutes in the U.S. and abroad said FIFA's heat safety protocols were highly inadequate and put players and spectators at severe risk. They wrote that science had shown more accurate wet bulb globe safety thresholds to be:
- 25 degrees Celsius (77 degrees Fahrenheit) for high exertion
- 28 degrees Celsius (82.4 degrees Fahrenheit) for moderate exertion
- 30 degrees Celsius (86 degrees Fahrenheit) for light work
- 33 degrees Celsius (91.4 degrees Fahrenheit) at rest
FIFA protocols also rely on two mandatory three minute hydration breaks midway through each half, but the scientists contend that neither that nor a wet bulb protocol that entrusts match postponement decisions to competition organizers are sufficient protections.
The scientists acknowledged that though professional athletes are likely to have "higher resilience compared to the baseline population," it still "is impossible to justify" FIFA's heat policy as adequate for health safety.
We respectfully urge FIFA to adopt heat management protocols that prioritize prevention over response, and that align with contemporary exercise physiology, occupational health principles, and duty of care standards expected in elite sport.
The hydration breaks are not long enough, they contend, to sufficiently cool core body temperatures and therefore "the risk of exertional heat illness increases sharply."
