The World Cup Is a Celebration of Sport. It’s Also a Warning About Climate Change.

Over the next month, millions of fans will gather across North America for the FIFA World Cup. Stadiums will fill with cheering crowds. Young athletes will dream of representing their countries one day. Communities will celebrate one of the world’s most beloved sporting events.

While we’re excited to welcome fans from around the world, we’re also concerned about a growing health threat already shaping this tournament: extreme heat.

The 2026 World Cup will be played during the hottest months of the year in an environment that is significantly warmer than it was when the U.S. last hosted the tournament in 1994. The conditions facing players, fans, and workers are not just a challenge for this year’s matches — they are a preview of how climate change is reshaping sports and outdoor activities globally.

A World Cup in a Warming Climate

A recent NPR analysis found that more than one-third of the tournament’s 104 matches face a high risk of dangerously hot and humid conditions. Some of the matches at greatest risk include marquee events such as the World Cup final and the third-place match. Climate experts have reached similar conclusions: an analysis by World Weather Attribution found that roughly one-quarter of World Cup matches could be played under conditions that pose elevated health risks to players and spectators. Five matches could face conditions severe enough to warrant postponement under international heat-safety guidelines.

These findings are consistent with a broader trend. Climate Central recently reported that extreme heat has increased across nearly every World Cup host city compared to previous decades. In some locations, extremely hot summer days occur several times more often than they did when earlier tournaments were held.

The reason is clear: Our planet is getting hotter. As healthcare providers, we see how heat turns quickly from discomfort into medical risk.

Heat Is More Than an Inconvenience for Players

When most people think about extreme heat at sporting events, they picture discomfort — players sweating through a match or seeking shade during halftime. But heat is a serious public health issue that affects every body system. High temperatures can cause dehydration, heat exhaustion, heat stroke, kidney injury, cardiovascular strain, and worsening respiratory conditions.

As super-human as athletes may appear, they are not immune. Heat can impair performance, slow reaction times, increase fatigue, and increase the risk of serious medical emergencies.

We have already seen examples of these dangers. During a recent international soccer competition in Kansas, a referee collapsed from heat illness and was taken out on a stretcher. Players have reported dizziness, dehydration, and other symptoms associated with extreme heat exposure. Professional athletes and coaches have increasingly voiced concerns about the impact of rising temperatures on player safety and performance.

It’s Not Just the Players

Players are not the only ones at risk. Millions of fans will spend hours outdoors before they ever reach their seats. They will stand in security lines, walk long distances, navigate unfamiliar transit systems, and spend extended periods in direct sunlight. Children, older adults, pregnant people, and individuals with chronic medical conditions face especially high risks. Visitors may also be vulnerable if they are not acclimated to local heat. Many will also drink alcohol, which can worsen dehydration, impair judgment, and make it harder to recognize early signs of heat illness.

Workers face even greater exposure. Stadium employees, security personnel, vendors, transportation workers, emergency responders, and volunteers may spend entire shifts in the heat, often in assigned posts with limited control over when they can rest, cool down, move into shade, or get water. These exposures worsen productivity, increase the risk of occupational injuries, and leave workers vulnerable to both acute and chronic heat illness impacts.

Compounded Health Impacts of Extreme Heat

Heat-related illnesses can escalate rapidly, particularly when large crowds are involved. In addition to acute heat illness, heat exposure worsens a plethora of chronic diseases, including cardiac, renal, respiratory, and mental health conditions. Cytokines and other inflammatory mediators contribute to multiorgan stresses that extend well past the time of exposure.

Fans and workers are often unaware that numerous common medications impair the body’s thermoregulation and increase heat illness risk. Anticholinergics and a variety of other medications used for cardiac, endocrine, and mental health diagnoses are especially risky in the heat. Diuretics, blood-pressure medications, antihistamines, and certain psychiatric medications can also make it harder for the body to cool itself. For many patients, even a single day of heat exposure poses a risk for worsening their chronic conditions.

What the Future of Sports Could Look Like

Sports have long adapted to protect athletes, from rule changes to equipment and medical protocols. Climate change is now forcing another adaptation.

FIFA has announced measures designed to reduce heat-related risks, including hydration breaks, cooling systems near team benches, enhanced medical support, and heat monitoring. These protections are important and should become standard practice whenever conditions warrant them. But adaptation alone has limits.

In an open letter to FIFA, international experts in health, climate, and sports performance warned that FIFA’s current heat-safety measures are “inadequate,” and need to be “evaluated and updated on the basis of the best available science.”

The fact that the World Cup final is scheduled to begin in the afternoon — the hottest part of the day — in an uncovered stadium highlights the difficult choices sports organizations increasingly face. Television schedules, venue logistics, and commercial considerations often compete with health and safety concerns.

This challenge extends far beyond professional soccer. Youth sports leagues are already grappling with canceled practices, shortened games, and heat-related illnesses. High school athletes, recreational leagues, and outdoor workers are experiencing many of the same risks that will be on display during the World Cup.

Protecting Health On and Off the Field

We believe there are actions we can take to help keep people safe.

Communities hosting major sporting events should invest in robust heat preparedness plans. That means ensuring access to water, cooling stations, shaded areas, emergency medical services, and clear public communication about heat risks. Emergency response and surveillance are necessary, but they are not enough. Heat illness is largely preventable, but only when protections reach people before they are in crisis.

Health professionals can help by educating patients about heat illness, supporting local emergency preparedness efforts, and speaking publicly about the health impacts of extreme heat. But we also have a responsibility to address the root causes.

The same pollution driving climate change is contributing to worsening air quality, longer wildfire seasons, more extreme weather events, and rising rates of heat-related illness. Heat and poor air quality also compound each other, creating a dual threat for cardiovascular and respiratory health when high temperatures coincide with ozone, wildfire smoke, or other air pollution.

A recent modeling study projected that heat-related cardiovascular disease burden will triple by 2050. Policies that reduce climate pollution, expand clean energy, strengthen community resilience, and protect vulnerable populations are also public health interventions.

As health professionals, we are trained to do more than treat symptoms. We work to prevent illness before it occurs. Climate change deserves the same approach.