World Cup Heat: A Dangerous Experiment for Players and Fans
The World Cup promised a festival of football across the US, Mexico and Canada. Instead, the opening round has doubled as a live experiment in how far elite players – and everyone around them – can be pushed in dangerous heat.
A Guardian analysis of the first 24 matches, one for each team, shows that two games were played in conditions so severe that the global players’ union Fifpro has previously said they should trigger a delay or postponement. Four more kicked off in cities where the heat passed that same red line, with only stadium air conditioning keeping conditions on the pitch just about playable.
Games on the edge
The most extreme match so far came in Miami, where Saudi Arabia faced Uruguay. It was an evening kick-off, but the numbers told a brutal story: a wet-bulb temperature of 28C (82F) or higher, a level Fifpro has argued should mean football stops.
Sweden v Tunisia in Monterrey was not far behind, the second most severe of the non-air-conditioned venues in the opening round, again played in punishing wet-bulb conditions of 28C or more.
Those two were not isolated outliers. In total, six of the first 24 fixtures took place in locations where the wet-bulb temperature hit at least 28C – Germany v Curacao in Houston, Saudi Arabia v Uruguay in Miami, Portugal v DR Congo in Houston, the Netherlands v Japan in Dallas, and England v Croatia, also in Dallas. Houston and Dallas both benefited from air-conditioned arenas, a technological safety net that several other venues do not have.
This World Cup is forecast to be the hottest since the competition began in 1930. That prediction is already biting.
What the numbers really mean
Wet-bulb temperature is not a standard forecast line on a TV graphic. It is a measure of heat stress that blends air temperature, humidity and cloud cover to gauge how effectively the human body can cool itself through sweating.
Once heat and humidity climb past a certain point, sweat simply cannot evaporate fast enough. The body overheats. Illness can follow quickly. In the worst cases, so can death.
To assess the opening round, the Guardian drew on weather data from government agencies in the US and UK, then calculated wet-bulb readings using a formula employed by authorities in several countries, including Australia and Canada.
Fifpro has previously argued that matches played at 28C wet-bulb or above should be delayed or postponed. Asked specifically about these World Cup findings, the union declined to comment on the current situation.
FIFA’s response under the spotlight
Faced with a roasting North American summer, FIFA has already moved some kick-off times later into the day and brought in mandatory water breaks. A handful of the 16 venues have roofs or full stadium air conditioning, which has softened the worst of the heat for players.
The most striking example came on Wednesday in Dallas, where England met Croatia. Outside, the wet-bulb temperature pushed close to 35C (95F), the fiercest reading of the tournament so far. Inside, the air conditioning dragged that down to around 22C (71F), a difference that turned a potential health crisis into a bearable, if still draining, environment.
Current FIFA guidelines say cooling breaks should be used when matches are played in heat of 32C (89F) or above. In practice, drinks breaks have been granted at lower temperatures during this World Cup. Any delay or suspension of play remains at the discretion of competition organisers.
On the eve of the tournament, a group of heat and public health experts wrote an open letter urging FIFA to go further, explicitly backing Fifpro’s call for games to be halted once wet-bulb temperatures reach 28C.
Robbie Parks, an environmental epidemiologist at Columbia University and one of the signatories, warned that official readings can underplay the true risk.
“Temperatures are often taken from shaded areas and if players are in direct sun, it can be double figures more than the temperature readings,” he said. “Standing in the sun can be dangerous even at lower temperatures, even above 23C (73F) or 25C (77F) would make me concerned for older adults out there for more than few minutes.”
Parks acknowledged that air conditioning, later kick-offs and water breaks will help players, but stressed that fans and stadium workers remain exposed.
“Shade is super important and hydration is super important,” he said. “You need to allow people to bring in their own water and think about having misters for evaporative cooling. The final is going to be held in New Jersey, and that stadium isn’t covered which makes me worry. But I’d hope Fifa will learn the best way to deal with that by then.”
Fans and workers in the firing line
Record-high temperatures in several host cities have already taken a toll in the stands and on the concourses. Some supporters have wilted in shadeless sections, left to endure the full force of the sun while the football plays out below.
The risks are even sharper for stadium workers, many of whom labour for hours before kick-off hauling equipment and setting up infrastructure in exposed conditions. Their workload does not come with tactical timeouts.
Extreme heat is the deadliest climate-related hazard on the planet, claiming more lives each year than hurricanes, floods and wildfires combined. This World Cup will add to the problem. With more than 100 matches spread across a continent, the tournament is expected to generate around 7.8m tonnes of greenhouse gases, according to estimates by the carbon accounting platform Greenly – roughly double the emissions of the previous World Cup in Qatar.
FIFA’s mitigation plan
FIFA insists it is prepared. A spokesperson said the governing body is “committed to protecting the health and safety of all players, referees, fans, volunteers and staff” at this World Cup.
Meteorologists have been stationed at match venues to help plan for extreme weather, and tournament preparation has involved “close coordination” with host city organisers, stadium authorities and national agencies.
Ahead of the competition, FIFA agreed what it calls a “tiered mitigation model” for extreme temperatures, with specific interventions activated at different thresholds.
For players, that means mandatory hydration breaks, ready access to water and electrolyte drinks, and a suite of cooling tools – ice, cold towels, fans, mist and shade where possible.
For spectators, elevated temperatures trigger extra measures: increased stadium cooling capacity, more shaded areas, misting systems, cooling buses and expanded water distribution.
A medical “set-piece protocol” has also been introduced for treating heat exertion, including the use of cooling bags for the first time at a World Cup.
FIFA says it will “continue to monitor conditions in real time, integrating wet bulb globe temperature and heat index surveillance, and stands ready to apply established contingency protocols should extreme weather events occur.”
The matches will keep coming, the stakes rising, the schedules tightening. The question now is whether football’s governing body will be forced to choose, in full view of the world, between the rhythm of a global showpiece and the limits of the human body in a rapidly warming climate.
