The 2026 FIFA World Cup may deliver football on an unprecedented scale, but scientists and players’ representatives are warning that soaring temperatures across North America could turn parts of the tournament into a dangerous test of endurance.
An analysis by climate research group World Weather Attribution found that nearly a quarter of the 104 matches scheduled across the United States, Mexico and Canada are likely to be played in heat conditions exceeding safety thresholds recommended by global players’ union FIFPRO.
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Researchers said around five matches could be played in conditions considered unsafe enough to warrant postponement.
The warnings have reignited concerns over player welfare less than a year before football’s biggest tournament expands to 48 teams and stretches deep into the North American summer.
Scientists used kickoff schedules and the Wet Bulb Globe Temperature (WBGT) index — which measures heat stress by combining temperature, humidity, wind and solar radiation — to estimate the risks players and spectators could face.
Their findings suggest the threat has intensified sharply since the 1994 World Cup in the United States, with the probability of dangerous heat now nearly double what it was three decades ago.
“The calculations to estimate the likelihood of 2026 FIFA World Cup games being played in high WBGT conditions are in line with FIFPRO's calculations published in 2023,” said FIFPRO medical director Vincent Gouttebarge.
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“These estimations justify the need for - and implementation of - a series of mitigation strategies with a view to better protecting players' health and performance when they are exposed to hot conditions.”
FIFPRO recommends mandatory cooling interventions when WBGT exceeds 26 degrees Celsius and says matches should be postponed once levels cross 28C — conditions roughly equivalent to 38C in dry heat or 30C in high humidity.
FIFA said it has already prepared a range of heat-management measures, including three-minute hydration breaks during each half, cooling infrastructure for players and fans, adjusted work-rest schedules and enhanced medical protocols tied to real-time weather conditions.
“FIFA is committed to protecting the health and safety of players, referees, fans, volunteers and staff,” the governing body said in a statement to Reuters.
The risk, however, extends beyond players sprinting under stadium lights.
Several host cities expected to stage matches with elevated heat exposure — including Miami, Kansas City, New York and Philadelphia — do not have air-conditioned stadiums, according to the analysis.
Even the final at MetLife Stadium in New Jersey faces mounting heat concerns. Researchers estimate the showpiece match now carries a one-in-eight chance of exceeding the 26C WBGT threshold and roughly a 3% probability of reaching more dangerous levels — about double the risk compared with 1994.
Scientists say the effects may reshape the football itself.
“It will be more of a performance issue than a health issue,” said Chris Mullington, consultant anaesthetist at Imperial College London NHS Trust and clinical senior lecturer at Imperial College London.
“These players are elite athletes and acclimatised. You'll see players self-pacing. That behavioural thermoregulation is very difficult to override.
“So you may end up with more conservative football.”
Climate experts say the findings also raise broader questions about whether summer tournaments in increasingly hot regions remain viable.
Friederike Otto, professor of climate science at Imperial College London, said FIFA may eventually need to rethink the calendar itself.
“From a health point of view, it would be advisable to have these (World Cups) either earlier or later in the year, so you can have a football party rather than something that is a massive health risk for the whole city,” Otto said.
FIFPRO warned that while climate-controlled stadiums in cities such as Dallas and Houston could offer some protection inside venues, supporters travelling between matches, waiting outdoors and gathering in fan zones may still face prolonged exposure to dangerous heat.
An analysis by climate research group World Weather Attribution found that nearly a quarter of the 104 matches scheduled across the United States, Mexico and Canada are likely to be played in heat conditions exceeding safety thresholds recommended by global players’ union FIFPRO.
Also Read: Delhi HC seeks Centre's stand on plea for FIFA World Cup broadcast
Researchers said around five matches could be played in conditions considered unsafe enough to warrant postponement.
The warnings have reignited concerns over player welfare less than a year before football’s biggest tournament expands to 48 teams and stretches deep into the North American summer.
Scientists used kickoff schedules and the Wet Bulb Globe Temperature (WBGT) index — which measures heat stress by combining temperature, humidity, wind and solar radiation — to estimate the risks players and spectators could face.
Their findings suggest the threat has intensified sharply since the 1994 World Cup in the United States, with the probability of dangerous heat now nearly double what it was three decades ago.
“The calculations to estimate the likelihood of 2026 FIFA World Cup games being played in high WBGT conditions are in line with FIFPRO's calculations published in 2023,” said FIFPRO medical director Vincent Gouttebarge.
Also Read: US relaxes visa bonds for World Cup fans
“These estimations justify the need for - and implementation of - a series of mitigation strategies with a view to better protecting players' health and performance when they are exposed to hot conditions.”
FIFPRO recommends mandatory cooling interventions when WBGT exceeds 26 degrees Celsius and says matches should be postponed once levels cross 28C — conditions roughly equivalent to 38C in dry heat or 30C in high humidity.
FIFA said it has already prepared a range of heat-management measures, including three-minute hydration breaks during each half, cooling infrastructure for players and fans, adjusted work-rest schedules and enhanced medical protocols tied to real-time weather conditions.
“FIFA is committed to protecting the health and safety of players, referees, fans, volunteers and staff,” the governing body said in a statement to Reuters.
The risk, however, extends beyond players sprinting under stadium lights.
Several host cities expected to stage matches with elevated heat exposure — including Miami, Kansas City, New York and Philadelphia — do not have air-conditioned stadiums, according to the analysis.
Even the final at MetLife Stadium in New Jersey faces mounting heat concerns. Researchers estimate the showpiece match now carries a one-in-eight chance of exceeding the 26C WBGT threshold and roughly a 3% probability of reaching more dangerous levels — about double the risk compared with 1994.
Scientists say the effects may reshape the football itself.
“It will be more of a performance issue than a health issue,” said Chris Mullington, consultant anaesthetist at Imperial College London NHS Trust and clinical senior lecturer at Imperial College London.
“These players are elite athletes and acclimatised. You'll see players self-pacing. That behavioural thermoregulation is very difficult to override.
“So you may end up with more conservative football.”
Climate experts say the findings also raise broader questions about whether summer tournaments in increasingly hot regions remain viable.
Friederike Otto, professor of climate science at Imperial College London, said FIFA may eventually need to rethink the calendar itself.
“From a health point of view, it would be advisable to have these (World Cups) either earlier or later in the year, so you can have a football party rather than something that is a massive health risk for the whole city,” Otto said.
FIFPRO warned that while climate-controlled stadiums in cities such as Dallas and Houston could offer some protection inside venues, supporters travelling between matches, waiting outdoors and gathering in fan zones may still face prolonged exposure to dangerous heat.
