The men's soccer World Cup kicks off next week at 16 stadiums across North America, just as summer weather arrives in many of the host cities. Millions of fans, players and workers could be exposed to potentially harmful heat, an NPR analysis finds.
More than one-third of World Cup matches are at high risk for dangerously hot, humid conditions, NPR found, and dozens more matches come with moderate heat risk.
NPR looked at two decades of temperature data for each host city, as well as the time each World Cup match is scheduled to start, and checked those temperatures against heat hazard guidelines from the Occupational Safety and Health Administration and the American College of Sports Medicine.
The high-risk events identified in NPR's analysis include multiple high-profile matches, such as the game that determines which team takes home third place in the World Cup, and the World Cup final.
"Players can overheat, and match officials as well," says Donal Mullan, a climate scientist at Queen's University Belfast, who co-authored a study last year about heat risk at the 2026 World Cup.
"They can also overheat and collapse," Mullan warns. "This has happened to people."
In an email to NPR, a spokesperson for FIFA, the governing body for international soccer, wrote that the organization "is committed to protecting the health and safety of players, referees, fans, volunteers and staff."
FIFA scheduled many games for cooler afternoon and evening hours, added extra water breaks for players and referees and installed air conditioning on the sidelines for those who are sitting on the benches, the email states.
"Outdoor matches during the hottest parts of the day have been strategically limited, kick-off times adjusted in certain markets, and matches expected in warmer windows prioritized for covered stadiums where possible," the email also states. FIFA did not respond to further questions about why some matches were nonetheless scheduled for high-risk locations and times.
When the weather is especially hot, "spectators will be permitted to bring one factory-sealed water bottle, and venues will activate additional cooling capacity, including shaded areas, misting systems, cooling buses and expanded water distribution," the FIFA spokesperson wrote to NPR.
FIFA did not respond to questions about how hot it would need to be to trigger protections, whether every venue has misting systems available or whether workers at stadiums would have the same access as spectators.
Dangerous heat and limited cooling
Out of the 104 games, 67 of them are being held at locations and times that come with potential danger for heat illnesses, with 39 of those at high risk, according to their historical wet bulb globe temperature (WBGT). The WBGT measurement is a strong indicator of overall heat risk because it takes into account humidity, shade and solar radiation to calculate the temperature.
"All hot weather is dangerous, but hot, humid weather tends to be more dangerous," says Jennifer Vanos, who studies heat policy at Arizona State University.
Miami, Houston, Dallas and Atlanta rank near the top in temperature for their games, with averages as high as 84 degrees Fahrenheit. Attendees and workers in those stadiums will have air conditioning.
Stadiums in other parts of the U.S. don't have the same infrastructure, with games in Philadelphia, New Jersey and Kansas City, Mo., averaging as high as 79 F with no roofs covering their stadiums.
Miami's stadium is the hottest venue without air conditioning. The historical average temperature this time of year is around 80 F. That threatens multiple matches with dangerously hot weather, including the match that determines which team wins third place in the tournament.
Multiple scientific studies have come to similar conclusions, including one published last month by researchers at Imperial College London and collaborators, who found that about a quarter of World Cup games this summer are likely to be held while temperatures exceed 79 F.
It is possible that individual matches in Miami and other high-risk cities will get lucky and see overcast skies and cooler-than-average temperatures. But climate change makes such luck less likely. Overall summer temperatures across North America are steadily rising, as global warming drives longer, hotter heat waves. The last 10 years were the hottest decade ever recorded on Earth.
The risk is not theoretical
The dangers of hot, humid weather are not new to professional soccer players and tournament organizers, though the risks are getting more pronounced as the planet warms.
The last men's World Cup tournament was held in the winter because of concerns about dangerously hot, humid weather in the host country of Qatar. Summer weather in Qatar's capital is often so hot and muggy that the human body can no longer cool itself by sweating.
Many North American cities also get extremely hot and humid, and heat emergencies have happened at professional soccer matches in the United States in the past.
Two years ago, hot, humid weather caused a health emergency at a stadium in Kansas City, Kansas. During a June 25, 2024, international soccer match, referee Humberto Panjoj collapsed on the field due to heat illness and had to be rushed to the hospital.
A nearby stadium in Kansas City, Mo., will host the World Cup match between Tunisia and the Netherlands exactly two years later, on June 25, 2026, raising concerns about the safety of conditions during that upcoming game.
At another 2024 match, held in Miami, a star player for Uruguay left the game at halftime and later told The Athletic that he suffered from dizziness and dehydration.
In 2017, professional soccer player Rachel Daly collapsed due to heat exhaustion during a match in Houston, despite additional water breaks during the game. She recovered and later posted on X: "those conditions are not safe to play at your maximum."
The sport's largest players union, FIFPRO, has expressed concern about player safety at the 2026 World Cup. FIFPRO did not respond to specific questions from NPR about heat safety at the tournament.
The reasons for avoiding the heat of the day go beyond protecting player and fan health. Soccer is a more dynamic game when it's played in cooler weather, studies have found, because players run faster and cover more ground.
Evening games are safer than afternoon ones
One of the simplest ways to protect people from hot weather during the World Cup is to schedule games for the evening, when temperatures are slightly cooler and there is less direct sunlight.
"The heat risk goes down significantly after about 6 o'clock in the evening, typically," Mullan says. "FIFA have by and large avoided the worst times of the day."
In an email to NPR, a FIFA spokesperson wrote that the organization took such considerations into account when it created the World Cup schedule.
FIFA did not answer questions about why the World Cup final is scheduled for the heat of the day, 3 p.m., on July 19 at an uncovered stadium outside New York City.
That start time, during the hottest part of the day, may have been chosen to maximize the global audience, much of which is located in later time zones. An evening start time would have required fans in Europe, Africa and Asia to tune in late at night or in the very early morning.
But the heat risk at that match is clear, Mullan says. "Obviously, if you schedule these matches for the midafternoon at some of these hottest locations, then that's your recipe for disaster," he explains. NPR's analysis found that the World Cup final match is likely to see wet bulb globe temperatures of 79 F, putting players and fans at risk for dangerously hot, humid weather.
World Cup fans and workers are also at risk for heat illness
The players and referees running around on the field are not the only ones at risk from very hot weather. Spectators and workers are also threatened.
That's because you don't need to be exercising to be affected by heat illness.
"I think about the person dying at the Taylor Swift concert in Brazil," says Vanos, of Arizona State University. In 2023, a Brazilian university student died while waiting for a brutally hot concert by the pop star.
In 2024, more than 1,300 people died during the Hajj, when that pilgrimage coincided with very hot weather in Saudi Arabia.
Both of those tragedies occurred during heat waves, when temperatures exceeded 100 F. While average summer temperatures in World Cup host cities generally remain lower than that, North American heat waves in recent years have led to triple-digit temperatures. And climate change means record-breaking heat waves are happening more often.
Vanos says large gatherings, like concerts, pilgrimages and sporting events, exacerbate the threat posed by heat because people are in large crowds, often visiting areas they are unfamiliar with. "Understanding the local context of the climate, where you can go to get water, where the water is safe, where you can go to find air conditioning — all of these things that sometimes it's easy to take for granted, but that can actually be really hard to find and get if you're in a really different context that you've never been in before," Vanos explains.
More than 6 million tickets are available for World Cup matches, according to FIFA, although the organization is not disclosing exactly how many it has sold.
Such a large event requires thousands of extra workers and overtime hours for local employees, many of whom will be working outside. The federal government is spending $625 million on local security in U.S. host cities — for example, NPR member station KCUR reports that Kansas City is using $59 million of that funding to cover police overtime at matches and extra officers from other locations.
Vanos says such workers could face dangerously hot conditions, especially if they're exposed to the sun during the hottest part of the day. The Occupational Safety and Health Administration recommends that workers be given water and shade breaks to prevent heat illness, but some states, including Florida, do not have laws on the books to enforce such recommendations.
This story was edited by Neela Banerjee. The graphics were edited by Alyson Hurt.
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