On a Saturday morning in August 2020, when the temperature was climbing toward 111 degrees, John and Valerie Thomas watched their son Shane finish soccer practice from a shaded area near the field. He looked fine. He was joking with his coaches.
Then he didn’t come back.
His teammates found him unresponsive near the batting cages, about 400 yards from the field. He was 17.
The San Bernardino County, California, coroner would later rule his cause of death was hyperthermia due to the heat.
“No one should have to go to practice with heat and come home without their kid,” John said afterward. In the years since, he has pleaded with club and state officials to create mandatory protocols for extreme heat conditions.
“I would love for it to be the Shane Thomas rule,” he said. “We don’t want to place blame. But [the heat] was a clear, possible factor.”
It is a warning that one that the world’s most powerful sports governing body has still not fully heeded.
When the 2026 FIFA World Cup kicks off on June 11 across 16 cities in the United States, Mexico, and Canada, the biggest opponent may not be wearing a jersey. It will be the heat, a group of scientists are warning — and the communities standing in its way are disproportionately Black and Latino.
A new analysis by World Weather Attribution, released last month, found that roughly a quarter of the tournament’s 104 matches are likely to be played in conditions that exceed the safety threshold recommended by FIFPRO, the global players’ union. That’s nearly double the risk of the 1994 World Cup, the last time the United States hosted.
“Almost all of the host locations — 14 out of 16 of them — experience levels of extreme heat, which could be potentially dangerous to players, match officials, and possibly spectators,” said Donal Mullan, a senior lecturer at Queen’s University Belfast who led the research.
Extreme heat, which is the single largest cause of weather-related deaths and illnesses in the U.S., has been made significantly more dangerous by decades of fossil fuel consumption. In America, it lands hardest on Black and older communities.
Scientists are warning that the people most at risk this summer are the fans who may come with many co-morbidities that could be exacerbated by the heat and will be unprotected inside the stadiums and at watch parties. The people in those crowds are disproportionately Black and brown. The World Cup is a cultural institution, particularly for African, Caribbean, and Latino immigrants across America.
“People who have got medical comorbidities, such as heart disease, will go into that situation,” warned Chris Millington, a consultant anaesthetist and honorary senior lecturer at Imperial College London who contributed to the World Weather Attribution analysis. “And gradually they’ll get hotter and hotter and hotter.”
That’s hundreds of thousands of people gathering in outdoor stadiums, fan zones, and street watch parties across the hottest weeks of an American summer, many of them older, many with preexisting conditions. Researchers warn it could lead to excess deaths across the summer, even after the games end.
The study measures heat danger using Wet Bulb Globe Temperature, a composite index that accounts for humidity, radiant heat, and air movement. FIFPRO recommends mandatory cooling breaks when WBGT hits 26° C or 79° F and advises postponement at 28° C or 82° F. FIFA’s own threshold for considering postponement is 32° C or 90° F. That gap, scientists warn, is a matter of life and death.
As the games begin, the question remains, what do fans need to know to protect themselves this World Cup season.
Which host cities have the highest risk
The World Cup this summer is also on track to be the most polluting in history. Researchers from the Cool Down the Sport for Climate Action Network, Scientists for Global Responsibility, and the Environmental Defense Fund calculated that the 2026 games will generate over 9 million tons of carbon dioxide — about double the average for the past four World Cups combined. A million tons is the equivalent emissions of about 220,000 cars on U.S. roads for a year.
That means the tournament that will expose millions of fans to dangerous heat is itself one of the largest contributors to the warming that makes that heat possible.
At stadiums like Levi’s Stadium in Santa Clara, California, and Lumen Field in Seattle, the likelihood of hitting the dangerous threshold has more than doubled.
The Danger Tier: Near-Certain to Hit Unsafe Levels
Dangerous heat is essentially guaranteed to occur during the tournament window:
- Dallas (AT&T Stadium)
- Houston (NRG Stadium)
- Miami (Hard Rock Stadium)
- Kansas City (Arrowhead Stadium)
- Philadelphia (Lincoln Financial Field)
- Atlanta (Mercedes-Benz Stadium)
The Rapidly Worsening Tier: Risk Has Doubled or More Since 1994
These cities were manageable in 1994. Climate change has fundamentally changed the math:
- Los Angeles (SoFi Stadium)
- Seattle (Lumen Field)
- Santa Clara, California (Levi’s Stadium)
- New Jersey (MetLife Stadium)
It may even affect the quality of the games. “It will be more of a performance issue than a health issue,” Millington said. “You’ll see players self-pacing.”
What have players and fans experienced in previous games
Sixty current and former professional soccer players from around the world recently issued an open letter urging FIFA to update its heat guidelines for events happening under dangerous heat before the World Cup.
“It can make you feel light-headed, dizzy, experience fatigue, muscle cramps and worse. You can run less and it becomes impossible to play with the same intensity as with more average temperatures,” the players wrote.
An open letter written by scientists and researchers to FIFA went further, warning that the organization’s sponsorship deal with Aramco, the world’s largest oil producer, “actively undermines a future in which football can be played and enjoyed.”
The precedent is already written.
During last summer’s FIFA Club World Cup, also held in the United States, heat and storms interrupted six matches. A peer-reviewed study found that in 31 of the 57 games, the average WBGT exceeded 82° F. Amid a heat emergency in Philadelphia, then-Chelsea manager Enzo Maresca said it was “impossible” to train properly in the 99° F weather. Midfielder Enzo Fernandez said the 96° F heat during Chelsea’s semifinal was “very dangerous” — at one point, he “had to lie down on the ground” after feeling “really dizzy.” FIFPRO’s medical director, Vincent Gouttebarge, was direct: Those games should not have been played.
The warning from Copa America 2024 was even starker. In Kansas City — one of the host cities this summer — temperatures hit 93° F, and with humidity factored in, it felt like 103° F. Assistant referee Humberto Panjoj collapsed during a match and was hospitalized. Uruguay defender Ronald Araújo left at halftime after feeling dizzy. At the same time, when it felt like 103° F outside Arrowhead Stadium, it felt like that, or worse, in the neighborhoods where Black fans were watching from porches, parking lots, and outdoor viewing events with no cooling infrastructure in sight.
The researchers behind the World Weather Attribution analysis are clear about why this is happening: climate change. Since 1994, global temperatures have risen approximately 0.7° C. That fraction of a degree has translated into a measurable increase in heat risk at every single World Cup venue.
Friederike Otto, professor of climate science at Imperial College London, said the findings highlighted the need for FIFA to reconsider when future World Cups are scheduled as extreme heat gets worse.
“From a health point of view, it would be advisable to have these [World Cups] either earlier or later in the year, so you can have a football party rather than something that is a massive health risk for the whole city,” Otto said.
