Extreme Heat at 2026 FIFA World Cup Poses Serious Health Risks to Fans and Workers, Experts Warn
Key Insights
The 2026 FIFA World Cup could be the hottest in history, with 14 of 16 host cities likely to see dangerous heat levels and many matches held in open-air stadiums without cooling systems.
Physicians report heat-related illnesses among fans at early matches, with heat indices exceeding 100°F in Miami and temperatures well above 90°F in Philadelphia.
Spectators and stadium workers face higher risks than athletes, who have access to medical teams, cooling breaks, and carefully monitored conditions.
As the 2026 FIFA men's World Cup unfolds across the United States, Canada, and Mexico, physicians and public health experts are sounding alarms about extreme heat conditions that extend well beyond the players on the field, potentially endangering millions of fans and thousands of workers at outdoor venues.
"This could be the hottest World Cup in history," said Dr. Douglas Casa, board of trustees distinguished professor at the University of Connecticut and chief executive officer of the Korey Stringer Institute (search), where he studies the impacts of heat and hydration on athletes, military members and laborers.
The scope of the risk is unprecedented. When the U.S. last hosted the World Cup in 1994, 21 games were expected to take place in extreme heat, and three were deemed unsafe to play. This year, 14 of the 16 host cities are likely to see dangerous heat levels, and some stadiums will not provide cooling systems. A recent study found that, largely due to climate change, dangerous heat conditions are now nearly twice as likely as they were just a few decades ago.
Open-Air Stadiums Under Scrutiny
While some U.S. host cities with hotter climates—Atlanta, Houston, and Dallas—have air-conditioned indoor stadiums that may afford fans some protection, three cities have emerged as particular concerns: Miami, Kansas City, and Philadelphia. These locations are home to open-air stadiums with the potential to expose fans to "very high heat" and "very high humidity," according to Dr. Fabian Arous, a sports medicine physician at Children's Health Andrews Institute for Orthopedics and Sports Medicine.
"I would put all my red flags up for the city of Miami as my biggest place of worry," Casa said.
Miami is scheduled to host seven matches, while Kansas City and Philadelphia each have six. During Monday's World Cup match in Miami between Uruguay and Saudi Arabia, the heat index rose above 100 degrees Fahrenheit, said Dr. Jose Llach, regional medical director of emergency care centers with Baptist Health South Florida. "It's only going to get hotter here in Miami, because July is a hotter month compared to June," he added.
Early Signs of Heat Impact on Fans
Heat-related illness is already manifesting among spectators. During the Ivory Coast versus Ecuador match in Philadelphia on Sunday, there was a slight increase in heat-related complaints among fans treated at stadium medical facilities, with "temperatures well above 90," said Dr. Kathleen Faccio, an emergency medicine physician at Jefferson Abington Hospital who is collaborating with FIFA's medical team at Philadelphia's World Cup matches.
"The majority of people were presenting with some mild heat-related illnesses, mild heat exhaustion (search)," Faccio said. "Heat exhaustion specifically, which is the most common presentation that we see, can be a myriad of symptoms that includes headache, nausea, fatigue, abdominal cramping, leg cramps."
Faccio noted that she and her colleagues are preparing for upcoming matches by ensuring IV fluids are among the medical supplies on site. "There's going to be a lot of excitement, and a lot of families maybe tailgating in the parking lots. I do anticipate that even before the game starts, that we'll have some patients."
Spectators and Workers at Greater Risk Than Athletes
Casa emphasized that spectators and workers face a higher risk of heat-related illnesses than the athletes themselves. Players have access to medical teams, cooling breaks, elite training, and carefully monitored conditions. But many of the people who make the World Cup possible—including security guards, concession stand staff, and construction workers—may spend hours in the heat without the same relief, especially in outdoor stadiums.
The last men's FIFA World Cup, held in Qatar in 2022, was mired in controversy over concerns that migrant laborers worked in life-threatening heat and humidity. That event was held in November and December, with seven of eight stadiums covered and temperature-controlled. This summer, most World Cup matches will be held in outdoor venues.
At Miami Stadium, Jackson Health System (search) worked with FIFA to set up medical areas for spectators. "Heat is certainly on our concern list," said Dr. Hany Atallah, Jackson Memorial Hospital's chief medical officer. "We're making sure we have the right supplies available. If someone does need some IV fluids or other care, that we have those things available."
The Spectrum of Heat-Related Illness
Dr. Jonathan Bar, an emergency physician and director of emergency preparedness at Penn Medicine in Philadelphia, outlined the progression of heat-related conditions. "In the mild forms of it, you might get heat rash. This occurs when sweat clogs your skin pores, and that goes away with getting cool and gentle exfoliation," he said. "Heat cramps are kind of the next level up, where that's usually due to electrolyte issues, and so staying hydrated is really important."
On the more severe end, heat exhaustion (search) and heat stroke (search) represent life-threatening emergencies. "What really differentiates heat exhaustion from heat stroke is involvement of the central nervous system," Bar said, noting that symptoms of heat stroke include confusion, loss of consciousness, or seizures. "It's important to recognize it quickly, because these are life-threatening medical emergencies."
Casa, who survived a heat stroke (search) in 1985, emphasized that "the best treatment is cold water immersion."
Compounding Factors: Air Pollution and Infection Risk
The extreme heat also creates conditions that worsen air quality. When temperatures increase, ground-level ozone is more likely to form, and more frequent wildfires in many host cities could elevate levels of particle pollution. These pollutants can penetrate deep into the lungs, causing respiratory and cardiovascular harm.
Additionally, crowded spaces like stadiums, airports, and watch parties increase the risk of respiratory infections. In the United States, parainfluenza, human metapneumovirus, and rhinovirus/enterovirus are currently elevated, with COVID-19 elevated in some areas. With millions of people gathering from around the world, these illnesses could spread easily through the air.
Practical Guidance for Attendees
After facing pressure, FIFA changed its policy to permit ticketholders in the U.S. and Canada to bring one "soft, plastic, 20 ounces (590ml), factory sealed disposable water bottle" into any match. Casa advises fans to "drink that water up when you get in and then use the refilling stations or the bathrooms to replace the water."
Experts also recommend applying sunscreen at least 20 minutes before sun exposure and reapplying at least every two hours, wearing wide-brimmed hats and loose-fitting SPF clothing, and using portable fans or cooling towels. "Just soak it with some water in the bathroom, and put it on your neck when you're watching the game, and that goes a long way," Llach said.
For older adults, Faccio stressed the importance of packing medications normally taken around match time. "There are a lot of World Cup fans who are over 65, and we sometimes fail to remember the timing of medication is really important for this specific population."
Bar also cautioned that certain medications—including antihistamines, beta-blockers, diuretics, anti-psychotics, and stimulants such as ADHD medications or SSRIs—can interact with heat, potentially increasing the risk of heat-related illness.
Public Health Infrastructure Mobilizes
Local health departments are actively monitoring forecasts and coordinating responses. Lori Tremmel Freeman, chief executive officer of the National Association of County and City Health Officials, said Houston is expecting heat indices approaching 105 degrees Fahrenheit during the tournament. "Extreme heat remains the leading weather-related cause of death in the United States," she noted.
"The public health role would be to make sure that there are appropriate cooling tents and facilities and proper emergency partnerships in place that can address both people that might be overcome by heat but also making sure we prevent them from being overcome by heat," Freeman said.
FIFA has implemented a mandatory three-minute hydration break midway through each half regardless of weather conditions, and matches are more spread out than in the past, giving players three days of rest between games. Some matches in hotter regions have been scheduled at night. However, a letter signed by leading scientists warns that current protections may not be enough, and that stronger safety measures are needed to protect players' health.
The risks extend beyond stadiums. Watch parties and FIFA-sponsored Fan Festivals are being hosted in cities across the country. Evan Young, 31, attended the Decatur WatchFest outside Atlanta ahead of the U.S.-Paraguay match. "We got here at like 6 p.m. It's been pretty hot. I think it was 92 degrees when we left the house," he said, adding that he visited the event's cooling station, equipped with misting fans, at least four times that night.