Climate change could make nearly one in every four matches at the 2026 FIFA World Cup dangerously hot, researchers warned on Thursday.
A new study said rising temperatures in North America have sharply increased heat risks since the United States last hosted the tournament in 1994.
The 2026 World Cup will run from June 11 to July 19 across 16 stadiums in the United States, Mexico and Canada. Heat concerns have already pushed FIFA to require cooling breaks in both halves of matches.
Climate scientists from World Weather Attribution said players and fans now face a far greater threat from heat and humidity than they did during the 1994 World Cup.
Their study found that 26 of the 104 matches could be played in conditions of at least 26 degrees Celsius Wet Bulb Globe Temperature. This measure looks at heat, humidity, sunlight and wind to judge how well the human body can cool down.
FIFPRO says cooling breaks become necessary at that level because players face real physical strain.
Out of those 26 matches, 17 will be held in stadiums with cooling systems, which could lower the danger.
By comparison, researchers estimate that 21 matches during the 1994 World Cup would have reached the same heat level.
The report also warned that five matches could face conditions of 28C WBGT or more. FIFPRO advises delaying or postponing games at that stage because of serious health risks.
Researchers said this danger has almost doubled since 1994.
Friederike Otto, co-founder of World Weather Attribution, said fans may face even greater risks than players because they often stay outdoors without the same medical support.
Only three host stadiums in Dallas, Houston and Atlanta have full air conditioning.
The study added that more than one third of matches with notable heat risk will be played in venues without air conditioning.
Even the World Cup final at MetLife Stadium in New Jersey could face heat concerns. Researchers estimate a one in eight chance of conditions reaching 26C WBGT and a smaller but real chance of extreme 28C heat.
Otto said the possibility of the final being played in such dangerous heat should serve as a serious warning for FIFA and supporters.
