World Cup Faces Extreme Heat Risks During Matches
The World Cup has walked straight into the furnace.
An analysis of the opening round of group matches shows that two games were played in heat so severe it crosses a threshold that the global players’ union Fifpro has previously said should trigger delays or postponements. Four more kicked off in cities where conditions outside also breached that level, with only stadium air conditioning stopping the temperatures from becoming truly brutal on the pitch.
At the heart of it all sits Saudi Arabia v Uruguay in Miami. On paper, just another group game. In reality, the hottest of the first 24 fixtures played across the US, Mexico and Canada. Sweden v Tunisia in Monterrey was not far behind. Both were evening kick-offs. Neither enjoyed the protection of stadium air conditioning. Both were played in wet-bulb temperatures of 28C (82F) or higher.
That number is not just a statistic. Fifpro has long argued that when wet-bulb readings hit 28C or above, the game should stop – delayed or postponed for the sake of the players. Asked about these specific World Cup conditions, the union chose not to comment. The tournament, though, is already tracking towards being the hottest since the competition began in 1930.
Wet-bulb temperature is the measure that strips away the illusion of a simple thermometer reading. It blends air temperature, humidity and cloud cover to answer one blunt question: can the human body still cool itself by sweating? Once the combination tips too high, sweat stops evaporating effectively. Overheating comes quickly. Illness, and in extreme cases death, are no longer theoretical risks.
To assess the opening phase, the Guardian drew on weather data from US and UK government agencies, using a formula employed by authorities in countries such as Australia and Canada to calculate wet-bulb values. The picture that emerges is stark.
Matches Played in Extreme Conditions
Six of the first 24 matches were played where wet-bulb temperatures hit 28C or more:
- Germany v Curacao in Houston
- Saudi Arabia v Uruguay in Miami
- Portugal v DR Congo in Houston
- Netherlands v Japan in Dallas
- England v Croatia in Dallas
- and again England v Croatia, counted in the analysis for its indoor-outdoor contrast
Houston and Dallas at least offered air conditioning. Miami and Monterrey did not.
The contrast was underlined in Dallas on Wednesday. Outside, England’s meeting with Croatia unfolded in the fiercest wet-bulb conditions of the tournament so far, close to 35C (95F). Inside the closed, air-conditioned stadium, the temperature dropped to around 22C (71F). For players, it was the difference between a punishing shift and something closer to a normal elite fixture.
Not everyone had that luxury. Record-breaking heat in several host cities left fans baking in open concourses and exposed seating, some wilting in shadeless sections. Stadium workers, on site for hours before kick-off hauling equipment and servicing the event, faced far more hazardous exposure.
Fifa’s current guidelines say cooling breaks should be used when temperatures reach 32C (89F). In practice, referees have been stopping games at lower readings during this World Cup. Delays or suspensions remain at the discretion of the competition organisers, a flexible clause in a rigid climate.
On the eve of the tournament, a group of heat and public health experts warned that flexibility is no longer enough. In an open letter, they urged Fifa to introduce stronger protections, explicitly backing Fifpro’s line that matches should be subject to postponement once wet-bulb levels hit 28C.
“Temperatures are often taken from shaded areas and if players are in direct sun, it can be double figures more than the temperature readings,” said Robbie Parks, an environmental epidemiologist at Columbia University and one of the signatories. “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 welcomed air conditioning, later kick-off times and water breaks as partial answers for those on the pitch. His concern stretched further. Fans and workers, he argued, need more than a drinks pause and a prayer.
“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.”
The backdrop to all this is not a freak summer but a warming planet. Extreme heat is already the deadliest climate-related hazard on Earth, killing more people each year than hurricanes, floods and wildfires combined. The World Cup, sprawling across a continent with more than 100 matches, is set to add to the problem. Estimates from Greenly, a global carbon accounting platform, suggest the tournament will generate around 7.8m tonnes of greenhouse gases – roughly double the emissions attributed to the previous World Cup in Qatar.
Fifa insists it is not blind to the risk. A spokesperson said the governing body is “committed to protecting the health and safety of all players, referees, fans, volunteers and staff”. Meteorologists are stationed at match venues to track conditions and advise on preparations for extreme weather. Tournament planning, Fifa says, involves “close coordination” with host cities, stadium operators and national agencies.
Under a “tiered mitigation model” agreed before the competition, extra interventions kick in at different temperature thresholds. For players, mandatory hydration breaks sit alongside access to water and electrolyte drinks, ice, cold towels, fans, mist and shaded areas on the sidelines.
Spectators, Fifa says, should benefit from similar escalation. Elevated temperatures trigger “additional cooling capacity, including shaded areas, misting systems, cooling buses and expanded water distribution”. A new medical protocol for treating heat exertion has been rolled out, including the use of cooling bags for the first time at a World Cup.
The governing body stresses that it will keep monitoring conditions in real time, using wet-bulb globe temperature and heat index surveillance, and “stands ready” to activate contingency plans if extreme weather strikes.
For now, the tournament plays on in the heat, water bottles lined up, misting systems humming, meteorologists watching the numbers climb. The question is no longer whether climate will shape this World Cup, but how long football can keep outrunning the thermometer.
