The 2026 World Cup will be sweltering polar opposite to what football was designed for | OneFootball

The United Kingdom is sweltering through its earliest serious heatwave of the year, with commuters crammed onto baking trains and football fans already moaning about playing five-a-side in late-May sunshine.

It is uncomfortable enough in Manchester or London as temperatures creep up towards 30 degrees. Now imagine playing a World Cup quarter-final in Philadelphia or Dallas in mid-afternoon summer heat, with humidity trapping every drop of sweat, under the pressure of a billion watching eyes.

The closer the 2026 World Cup comes, the harder it is to ignore the uncomfortable truth hanging over FIFA’s grand North American spectacle: this tournament could become a live demonstration of elite sport colliding with climate reality.

The concerns are no longer hypothetical. A growing body of research suggests that dangerous heat stress will be one of the defining stories of the tournament across the United States, Mexico and Canada. A recent World Weather Attribution analysis warned that roughly a quarter of matches could be played in conditions exceeding recommended safety limits for elite footballers, with some fixtures potentially crossing thresholds where postponement would ordinarily be advised.

That analysis formed part of the backdrop to “Heat, Hype and High Stakes”, a recent media briefing organised by Pledgeball and Cool Down, during which scientists, player advocates and climate campaigners laid out the scale of the risk. Freddy Daled of Cool Down highlighted how climate change has sharply increased the probability of dangerous playing conditions compared with the last men’s World Cup hosted in North America in 1994.

The message was stark: this is not merely a conversation about discomfort or competitive balance, but one of player welfare and public health.

The key measurement underpinning the debate is Wet Bulb Globe Temperature, or WBGT, which factors in humidity, solar radiation and wind alongside ordinary air temperature. It matters because the human body cools itself primarily through sweat evaporation, and high humidity severely restricts that process. A dry 32°C day is demanding; a humid 32°C day under direct sun can become genuinely dangerous.

Researchers involved in the recent studies warned that conditions above 26°C WBGT already create moderate to high heat stress for elite athletes, while around 28°C enters territory where global players’ union FIFPRO recommends postponement should be considered.

FIFA’s own guidance remains more permissive. Under current regulations, suspension or postponement is only formally considered at WBGT levels above 32°C. Critics argue that threshold is far too high for a modern understanding of heat illness and exercise physiology.

To its credit, FIFA has at least acknowledged the problem. The governing body has introduced mandatory three-minute hydration breaks midway through each half at every match of the 2026 World Cup, regardless of venue or weather conditions. It has also established a Heat Illness Mitigation and Management Task Force, adjusted kick-off scheduling in some markets and pledged additional cooling infrastructure for supporters.

But many experts believe those measures remain inadequate against the scale of the threat. Researchers and player advocates have questioned whether FIFA’s thresholds are medically defensible, while medical specialists have questioned whether three-minute breaks can meaningfully reduce core body temperature in extreme conditions. Scientific literature around football performance in extreme environments increasingly emphasises the importance of pre-cooling strategies, cold-water immersion and carefully managed recovery protocols simply to reduce physiological strain.

The football consequences are obvious enough. Heat impairs sprint output, reduces high-intensity running and accelerates fatigue. Tournaments are already attritional without adding oppressive humidity and temperatures that leave players dizzy and cramping by half-time. Yet the broader concern is more serious. Heat exhaustion and heat stroke are not abstract risks for elite athletes repeatedly asked to perform maximally under heavy thermal stress.

That is why criticism from players themselves has grown louder. Morten Thorsby, long one of football’s most outspoken environmental campaigners, has been among those questioning whether FIFA’s approach adequately protects participants.

“For the players, it’s an obvious problem of heat impacting the performance. Obviously the intensity of the game goes down,” Thorsby, who played alongside Jamie Vardy at Cremonese in Italy, told BBC Sport.

“Football is also an entertainment industry. The spectacle and the show and the sport loses its value if the players are not able to perform at their best. Everybody in football loses by not tackling this.”

A wider group of current and former professionals recently signed an open letter calling for stronger safeguards and alignment with FIFPRO’s lower WBGT recommendations. The players warned that many already have direct experience of heat-induced dizziness, fatigue and muscular problems during matches.

And the danger does not stop at the touchline. Fans may in some cases face greater exposure than the players themselves. While some stadiums offer climate-controlled environments, supporters will often spend hours outdoors travelling, queueing and gathering in fan zones before kick-off. Scientists involved in the recent research warned that older supporters and those with underlying health conditions could be especially vulnerable.

The Guardian’s recent analysis of tournament conditions painted an alarming picture, particularly in cities such as Miami, Dallas and Philadelphia, where combinations of heat and humidity could push conditions into hazardous territory during afternoon kick-offs. Even ostensibly milder venues carry risk when direct sunlight and urban heat effects are factored in. The concern is compounded by the expanded format: 104 matches, more travel, more training sessions and less recovery margin across a sprawling continental tournament.

There is a grim irony in all this. FIFA has spent years presenting football as a vehicle for sustainability messaging, right down to slogans about showing a “green card for the planet”. Yet the 2026 World Cup increasingly looks like an event shaped – and endangered – by the accelerating climate crisis football itself cannot escape.

The uncomfortable reality is that elite football’s calendar was built for a different climate. Summer tournaments once meant sunshine and dehydration risk. Increasingly they mean extreme heat events, medical contingency planning and serious questions about whether certain kick-off times should exist at all. The Club World Cup in the United States already offered a glimpse of what is coming. The 2026 World Cup threatens to magnify it on the biggest stage the sport possesses.

Football has always demanded endurance. Rising temperatures and a lack of sufficient protocols could mean players are asked to endure conditions the modern game was never designed for.