World Cup Under Brutal Heat: Players' Safety at Risk
The World Cup promised a festival of football across the US, Mexico and Canada. It has opened instead under a brutal sun.
A Guardian analysis of the first round of group matches – the opening 24 games of the tournament – shows that two fixtures were played in heat so intense it crossed a safety line previously highlighted by the global players’ union Fifpro as a point at which matches should be delayed or postponed.
Four more games were staged in cities where conditions outside also passed that threshold, with only stadium air conditioning stopping them from becoming endurance tests as much as sporting contests.
Miami and Monterrey at the edge
The most punishing conditions came in Miami, where Saudi Arabia faced Uruguay. Even with an evening kick-off, the wet-bulb temperature – a key measure of heat stress that blends temperature, humidity and cloud cover – hit 28C (82F) or higher.
Sweden v Tunisia in Monterrey was next on the list among stadiums without air conditioning. Again, an evening slot offered little protection. The numbers still climbed to that same 28C mark and beyond.
For Fifpro, that figure is not just a statistic. The union has previously argued that once wet-bulb temperatures reach 28C, football should stop and wait. Matches, it says, ought to be delayed or postponed at that point. Asked about these findings, Fifpro declined to comment on the conditions at this World Cup, a tournament forecast to be the hottest in the competition’s history, stretching back to 1930.
The science behind the concern is stark. Wet-bulb temperature gauges how effectively the human body can cool itself through sweating. Once heat and humidity rise past a certain point, sweat no longer evaporates properly. The body overheats fast. Illness follows. In extreme cases, death.
Using data from government weather agencies in the US and UK, the Guardian calculated wet-bulb readings through a formula used by authorities in several countries, including Australia and Canada. The picture that emerges is of a World Cup being squeezed by the climate crisis as much as by its congested calendar.
Six games over the line
Across the first 24 matches, six were played in places where wet-bulb temperatures hit 28C or higher: 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’s stadium is among those fitted with air conditioning, a technological shield that has already become central to this World Cup.
In Dallas on Wednesday, England’s meeting with Croatia unfolded in the fiercest wet-bulb conditions yet recorded at this tournament – close to 35C (95F) outside. Inside, the stadium’s cooling system dragged that figure down to around 22C (71F), turning what could have been a dangerous spectacle into something closer to a normal elite match.
Not everyone is so protected. Record temperatures around some venues have left supporters wilting in shadeless concourses and open approaches to grounds. Stadium workers, many of them on their feet for hours, hauling equipment long before kick-off, are operating in what experts warn are potentially hazardous conditions.
Fifa’s thresholds under scrutiny
Fifa’s own guidelines still revolve around conventional temperature readings rather than wet-bulb measurements. The governing body recommends cooling breaks when matches are held in heat of 32C (89F) or above, though drinks breaks have been used at lower temperatures during this World Cup. Delaying or suspending games remains at the discretion of competition organisers.
That approach has come under pressure. On the eve of the tournament, a group of heat and public health specialists published an open letter urging Fifa to toughen its protections, explicitly citing Fifpro’s 28C wet-bulb threshold as a point at which games should be considered for postponement.
“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 letter’s 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 acknowledged that air conditioning, later kick-off times and water breaks offer some protection to players. The real gap, he argued, lies elsewhere. Fans and workers need more.
“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.”
Climate crisis at the heart of the tournament
The heat around this World Cup is not an isolated weather quirk. Extreme heat is the deadliest climate-related hazard on the planet, killing more people each year than hurricanes, floods and wildfires combined. The tournament itself will add to the problem.
More than 100 matches, long-haul travel and vast temporary infrastructure are expected to generate around 7.8m tonnes of greenhouse gases, according to estimates from the global carbon accounting platform Greenly. That figure is roughly double the emissions associated with the previous World Cup in Qatar.
The spectacle is, in effect, both a victim of rising temperatures and a contributor to them.
Fifa’s defence and the battle to keep cool
Fifa insists it is not blind to the risks. A spokesperson said the organisation 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. Tournament organisers are working, Fifa says, in “close coordination” with host cities, stadium authorities and national agencies. A “tiered mitigation model” has been agreed for extreme temperatures, with different interventions triggered at specific 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. For spectators, raised temperatures are supposed to activate extra cooling capacity at stadiums – shaded zones, misting systems, cooling buses and expanded water distribution.
A new medical protocol for treating heat exertion has also been rolled out, including the use of cooling bags for the first time. Fifa says it will continue to monitor conditions in real time, using wet bulb globe temperature and heat index surveillance, and stands ready to deploy contingency plans if extreme weather hits.
The numbers suggest that moment is already here. The World Cup has only just begun, yet players are already pushing their bodies to the edge of what sports science considers safe. As the tournament moves towards its climax, and with a roofless final scheduled for New Jersey’s summer glare, the question is no longer whether heat will shape this World Cup – but how far football is willing to bend before it finally says: enough.
