As the 2026 FIFA World Cup unfolds across 16 cities in the United States, Canada, and Mexico, concerns about extreme heat are emerging alongside the spotlight on the athletes and fans. Since the last North American World Cup in 1994, average global temperatures have risen approximately 1.3 degrees Fahrenheit, contributing to a significant increase in the frequency of hazardous heat conditions during the summer months. Experts warn that this warming trend poses serious challenges to player safety, fan comfort, and the broader future of international soccer.
This year’s tournament features 104 matches, the most ever scheduled, spread across ten U.S. cities that previously hosted World Cup games. Climate researchers from the World Weather Attribution (WWA) initiative at Imperial College London have found that the likelihood of extreme heat during June and July has tripled in these locations since 1994. Approximately one-quarter of the matches are projected to occur at wet bulb globe temperatures—a measure that accounts for heat, humidity, sunlight, and wind—above 26 degrees Celsius, the point where heat strain becomes a concern for athletes. Five games could even exceed 28 degrees, a level deemed unsafe by many health experts.
The wet bulb globe temperature threshold at which FIFA considers postponing a match is set at 32 degrees Celsius, a more lenient limit than recommended by organizations like the International Federation of Professional Footballers and the American College of Sports Medicine, which advise caution starting at 28 degrees. Physiologists caution that prolonged exposure to extreme heat can cause players’ core body temperatures to rise uncontrollably, increasing the risks of heat exhaustion and heat stroke. Mike Tipton, a human applied physiology professor at the University of Portsmouth, noted that higher temperatures tend to reduce player performance, with slower paces, fewer sprints, and an increased likelihood of games being decided by penalty shootouts.
Teams, including England, have been training in hot environments such as Miami to help athletes acclimate ahead of tournament play. FIFA has also implemented new measures aimed at protecting participants and spectators from heat-related hazards. For the first time, three-minute mandatory cooling breaks will be held midway through each half. Additionally, climate-controlled benches will be provided for substitutes and staff at outdoor stadiums, and several matches have been scheduled for evening hours to mitigate daytime heat exposure. Venues in Atlanta, Dallas, and Houston will feature climate control inside the stadiums, though experts note that fans in outdoor viewing areas and queues remain vulnerable to heat stress.
In a recent letter to FIFA, a group of 21 scientists, including physiologists and climate specialists, criticized the governing body for insufficient heat safety protocols and recommended more extensive cooling strategies, longer breaks, and improved locker-room environments to better protect players.
The dangers of extreme heat go beyond athlete safety. Climate scientist Joyce Kimutai of Imperial College highlighted that cities like Miami, Kansas City, and Philadelphia could experience wet bulb globe temperatures at or above the unsafe 28-degree Celsius mark, putting spectators—particularly the elderly, children, and those with preexisting health issues—at heightened risk. Experts urge fans to recognize early signs of heat illness such as dizziness, fatigue, rapid heartbeat, cramps, and tingling sensations and to seek shade, rest, and hydration promptly.
The opening match at Estadio Azteca in Mexico City, where Mexico faced South Africa on June 8, marked the beginning of a tournament that not only showcases soccer’s global reach but also reflects the undeniable impacts of climate change on international sport.