Extreme heat has always been part of outdoor sports, but some competitions are becoming increasingly difficult to stage safely when temperatures and humidity climb. That problem is not limited to recreational athletes. Even highly conditioned professionals can develop heat exhaustion or exertional heatstroke when their bodies generate heat faster than they can get rid of it.
One of the clearest examples came at the 2022 FIFA World Cup in Qatar. World Cups are traditionally played during the Northern Hemisphere summer, but FIFA moved that tournament to November and December specifically because of Qatar’s extreme summer temperatures. More recently, oppressive heat became one of the major storylines of the 2025 FIFA Club World Cup in the United States, with players and coaches openly complaining about conditions during afternoon matches.
The issue is hardly limited to soccer. Football teams begin training camps during some of the hottest weeks of the year. Baseball’s 2026 regular season began on March 25 and stretches through late September, putting players on outdoor fields throughout the summer. Tennis players, runners, golfers, and countless high school athletes can spend hours exercising under direct sunlight.
Heat illness can range from uncomfortable to life-threatening, and exertional heatstroke is a true medical emergency. The good news is that many serious cases are preventable when teams monitor environmental conditions, give athletes time to acclimatize, provide adequate hydration and rest, recognize symptoms quickly, and have an effective emergency cooling plan.
Which Sports Put Athletes in the Heat?
Almost any outdoor sport can expose athletes to dangerous heat, but the risk is not identical across activities. Football deserves particular attention because players combine intense exertion with helmets, pads, large body sizes, and preseason conditioning that often occurs in July and August. Research tracking U.S. secondary-school sports from 1982 through 2022 identified 67 deaths from exertional heatstroke. Football accounted for 63 of them.
That does not mean lighter uniforms eliminate the danger. Soccer players can cover several miles during a match, tennis players may compete for hours on sun-baked courts, and distance runners create enormous amounts of body heat even when the air temperature does not seem extraordinary. Humidity makes matters worse because sweat does not evaporate as efficiently, limiting one of the body’s primary cooling mechanisms.
Sports organizations increasingly use more than the ordinary air temperature to make decisions. Wet Bulb Globe Temperature, or WBGT, accounts for factors including temperature, humidity, wind, and radiant heat. Major League Soccer, for example, mandates cooling breaks when WBGT reaches its specified threshold, with additional drinks breaks available when referees believe player safety is at risk.
Soccer’s response has become even more visible. After extreme heat generated widespread criticism during the 2025 FIFA Club World Cup, FIFA announced that every match at the 2026 World Cup will include a three-minute hydration break about 22 minutes into each half, regardless of the weather. It is an acknowledgment that heat management is now part of planning major outdoor sporting events, not something organizers can simply deal with after players start struggling.
Baseball has its own mix of indoor and outdoor environments. Some hot-weather clubs play in retractable-roof or climate-controlled stadiums. Tropicana Field, which has a fixed dome rather than a retractable roof, historically protected the Tampa Bay Rays from Florida’s summer heat. Hurricane Milton destroyed much of that roof in October 2024, forcing the Rays to play the 2025 season outdoors at George M. Steinbrenner Field in Tampa. A new roof was installed, and the Rays returned to Tropicana Field in April 2026.
What Extreme Heat Does to an Athlete
The body cools itself largely by sending more blood toward the skin and producing sweat. During hard exercise, however, the muscles are generating additional heat at the same time. Hot and humid conditions can eventually push that cooling system beyond its limits.
Heat exhaustion commonly involves heavy sweating, weakness, dizziness, headache, nausea, thirst, and fatigue. Muscle cramping can also occur. An athlete showing those symptoms should stop exercising, move to a cooler location, and begin cooling and rehydration rather than trying to “tough it out.”
Heatstroke is much more serious. A dangerously elevated core body temperature accompanied by central nervous system problems such as confusion, unusual behavior, loss of coordination, seizures, or unconsciousness is a medical emergency. Contrary to a common misconception, someone experiencing exertional heatstroke may still be sweating heavily.
Rapid cooling is critical. Medical experts consider whole-body cold-water immersion the preferred treatment for exertional heatstroke when it is available. Emergency medical help should also be activated immediately. The longer dangerous hyperthermia continues, the greater the risk of injury to the brain, heart, kidneys, liver, muscles, and other organs.
Heatstroke Has Killed Athletes at Every Level
Perhaps the best-known case in professional American sports is Minnesota Vikings offensive lineman Korey Stringer. The 27-year-old Pro Bowler collapsed during training camp and died from exertional heatstroke on August 1, 2001. His death became a turning point in football’s approach to heat safety and eventually inspired the creation of the Korey Stringer Institute at the University of Connecticut, which focuses on preventing sudden death in athletes and others who work in extreme conditions.
College football confronted another devastating case in 2018. University of Maryland offensive lineman Jordan McNair developed heatstroke during a team workout on May 29 and died on June 13 at age 19. An independent review faulted the medical response, and Maryland subsequently implemented dozens of reforms, including emergency action plans and access to cold-water immersion at athletic activities.
The danger has not disappeared. In August 2024, 15-year-old Ovet Gomez Regalado collapsed following preseason football conditioning at Shawnee Mission Northwest High School in Kansas. A medical examiner later determined that he died from complications of heatstroke. The temperature was reportedly around 92 degrees with humidity above 70%, producing a heat index of at least 112 degrees.
The summer of 2024 also produced intense national coverage after several teenage football players died following practices or games within a matter of weeks. Not every death was ultimately attributed to heat, but the cluster renewed scrutiny of summer football practices and the availability of athletic trainers, WBGT monitoring, cold-water immersion tubs, and emergency response plans at high schools.
Elite athletes have sounded alarms as well. During brutally hot conditions at the 2023 U.S. Open, Daniil Medvedev memorably warned a courtside camera that a player was “gonna die” after struggling through a quarterfinal in temperatures approaching 95 degrees. Two years later, extreme heat again became a major player-welfare controversy during FIFA’s Club World Cup in the United States.
Severe Heatstroke Can Cause Lasting Damage
Most ordinary exposure to a hot afternoon does not automatically cause permanent damage. The real concern is severe heat illness, especially heatstroke. When body temperature remains dangerously high, the resulting stress can trigger inflammation, problems with blood clotting, muscle breakdown, and injury to multiple organs.
The kidneys are particularly vulnerable. During heat stress, more blood is sent toward the skin to help release heat while sweating causes losses of water and electrolytes. Severe hyperthermia can contribute to acute kidney injury, while muscle breakdown associated with serious exertional heatstroke can place even more strain on the kidneys.
The brain can also be affected. Heatstroke is defined in part by central nervous system dysfunction, and medical research has documented persistent neurological problems in some survivors. Severe cases have also been associated with longer-term cardiovascular and renal complications. Those outcomes are very different from simply feeling drained after a hot practice, which is why recognizing the transition from ordinary heat stress to a medical emergency matters so much.
How Athletes Reduce the Risk
Hydration matters, but “drink more water” is not a complete heat-safety plan. Athletes also need gradual heat acclimatization, appropriate work-to-rest ratios, access to shade or air conditioning, lighter equipment when possible, environmental monitoring, and coaches and medical personnel who are willing to stop activity when conditions become unsafe.
The CDC recommends moving outdoor workouts away from the hottest part of the day when possible, increasing intensity gradually, drinking before thirst becomes severe, and watching teammates for signs of trouble. Athletes who feel faint or weak should stop activity and get somewhere cool.
The biggest red flag is a change in mental status. Confusion, disorientation, collapse, seizures, or bizarre behavior during strenuous exercise in the heat should raise immediate concern for exertional heatstroke. That is not the time to sit an athlete on the sideline with a bottle of water and see whether things improve. Rapid cooling and emergency medical care can be lifesaving.
Sports are not going to stop because summer gets hot, but the old idea that heat is simply something athletes should push through is increasingly difficult to defend. From the NFL to FIFA to high school football fields, the lesson from decades of preventable tragedies is the same: heat has to be treated as a genuine opponent.