A group of world-leading scientists have warned FIFA that its current heat safety measures for the men’s 2026 World Cup are “inadequate” and could expose players to serious health risks.
In an open letter, international experts in health, climate and sports performance said FIFA’s guidelines are out of step with current science and “impossible to justify”.
They called for stronger protections, including longer cooling breaks and clearer rules for delaying or postponing matches in extreme conditions.
Rising heat risk across host countries
Heat is expected to be a major factor at the tournament, which will be hosted across the United States, Canada and Mexico.
Researchers say temperatures at 14 of the 16 stadiums could reach dangerous levels.
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In parts of the southern United States and northern Mexico, average daytime temperatures typically sit in the low to mid-30s °C and can rise close to 40 °C during hotter periods.
Scientists warn that when humidity, wind speed and solar radiation are factored in, players in several host cities face extreme heat stress conditions during matches.
FIFA maintains safety commitment
FIFA says it is “committed to protecting the health and safety of players, referees, fans, volunteers and staff” and that climate risks are built into its tournament planning.
Current heat mitigation measures
As part of its player welfare framework, FIFA has introduced mandatory three-minute cooling breaks in each half of every match, regardless of conditions.
All outdoor venues will also feature climate-controlled benches for technical staff and substitutes.
FIFA applies the Wet Bulb Globe Temperature (WBGT), the global standard for measuring heat stress in sport. A WBGT of around 28 °C is widely considered a threshold where heat becomes a serious concern for elite athletes.
According to FIFA’s emergency care manual, when WBGT levels approach or exceed 32 °C, match organisers are required to agree “what precautions need to be taken to prevent any heat-related illness from occurring”.
For fans, FIFA says additional measures will be activated when forecasts show high temperatures. These include allowing factory-sealed water bottles into stadiums and providing shaded areas, misting systems, cooling buses and expanded water distribution points.
Scientists propose stricter limits
The 20 experts behind the letter include academics from the United Kingdom, the United States, Canada, Australia and Europe.
They are calling for urgent changes, including:
1. Delaying or postponing matches above 28 °C WBGT
2. Extending cooling breaks to at least six minutes
3. Improving cooling facilities for players
4. Regular updates to guidelines based on new research
They also urged FIFA to align its protocols with standards proposed by the global players’ union FIFPRO.
Andrew Simms, director of the New Weather Institute, who coordinated the letter, said risks needed urgent attention.
“Player safety is an immediate and urgent concern because things can go wrong very quickly when people overheat.
“We’re worried that FIFA is playing recklessly with the health and safety of players.”
Professor Douglas Casa from the University of Connecticut also said current measures were insufficient.
“The hydration break in each half absolutely needs to be longer than three minutes – at least five minutes for each break and preferably six.
“We hope this open letter convinces FIFA to update its heat guidelines before the World Cup.”
Why the 2026 tournament is under scrutiny
Extreme weather is expected to shape conditions at the 2026 World Cup. Heat, thunderstorms, and poor air quality linked to wildfires are all forecast risks across the three host nations.
New analysis from the World Weather Attribution (WWA) suggests players and fans will face significantly higher exposure to extreme heat and humidity compared with the 1994 World Cup held in the United States.
Researchers found that about a quarter of matches could be played above 26 °C WBGT, while around five matches may exceed 28 °C WBGT, a level FIFPRO considers unsafe for play.
The WWA also says the likelihood of extreme heat conditions has nearly doubled since 1994 due to climate change.
FIFA defends approach
FIFA declined to respond directly to the letter or the scientists’ criticism but said it would use a “tiered heat mitigation model” during the tournament, adjusted to real-time conditions.
A spokesperson said dedicated meteorological teams would monitor conditions across all host cities, with WBGT and heat index data guiding decisions.
FIFA added that match scheduling has been designed with climate conditions in mind, including adjusted kick-off times, limiting matches during peak heat where possible, and assigning warmer fixtures to covered stadiums. It also said travel demands and rest periods had been factored into scheduling.
The governing body said it would continue to monitor conditions during the tournament and apply contingency measures where necessary, adding that it is working with host authorities and medical experts to ensure a “safe and resilient” World Cup.
