The problems heat causes during matches were visible during the 2025 Fifa Club World Cup, played in the same summer months and across many of the same North American venues. Players and managers repeatedly referenced the stifling weather conditions<\/a>.<\/p>\n Borussia Dortmund manager Niko Kova\u010d<\/a> said after a match in Cincinnati he was \u201csweating like I\u2019ve just come out of a sauna\u201d. Chelsea midfielder Enzo Fern\u00e1ndez<\/a> described conditions as \u201cvery dangerous\u201d, adding that \u201ceverything becomes very slow\u201d. Juventus manager Igor Tudor revealed that ten players asked to be substituted during a match against Real Madrid in Miami, where temperatures reached 30\u00b0C, with 70% humidity. <\/p>\n North America\u2019s last World Cup (USA 1994) also produced memorable scenes relating to heat. German striker J\u00fcrgen Klinsmann recalled: \u201cI played in Dallas at 120 degrees [49\u00b0C ] I was dying\u201d<\/a> in a match against South Korea. Meanwhile, Republic of Ireland manager Jack Charlton was reprimanded by Fifa officials for throwing water bottles<\/a> onto the pitch to help his dehydrated players during a game in Orlando.<\/p>\n Extreme heat is not just uncomfortable \u2013 it threatens both health and performance. Football already has documented cases of heat-related fatigue, collapses and hospitalisations, including Guatemalan referee Humberto Panjoj collapsing<\/a> during a 2024 Copa Am\u00e9rica match in Kansas City.<\/p>\n Heat also changes the game itself. Studies show<\/a> players cover less distance, perform fewer high-intensity sprints and get tired more quickly in extreme conditions. Tired players are more prone to mistakes and injuries, while hotter matches have been linked to more penalty shootouts<\/a>, as exhausted teams struggle to break each other down in extra time.<\/p>\n Scientists commonly use Wet Bulb Globe Temperature (WGBT)<\/a> to assess heat stress. Unlike air temperature alone, WBGT combines temperature, humidity, solar radiation and wind, making it a better indicator of how dangerous conditions feel to the human body.<\/p>\n Several football governing bodies \u2013 including the global players\u2019 union Fifpro<\/a> \u2013 consider a WBGT above 28\u00b0C to be a threshold where matches should potentially be delayed or postponed.<\/p>\n 20-year average levels of extreme heat in 16 venue cities<\/strong><\/p>\n A study I led<\/a> in 2025 found that 14 of the 16 upcoming World Cup host cities are likely to exceed the extreme 28\u00b0C WBGT threshold if conditions this summer are typical. Most of the danger falls during mid-afternoon, and Fifa has clearly tried to reduce some of the risk through scheduling. Compared with the Club World Cup, matches in the hottest cities and non-air-conditioned stadiums have largely been shifted away from the most dangerous hours of the day<\/a>.<\/p>\n That will help \u2013 but it will not eliminate the problem.<\/p>\n Some high-risk fixtures remain. Late afternoon (5pm) and early evening (6pm) matches in Miami and Kansas City carry a greater than 30% risk of WBGTs exceeding 28\u00b0C if summer temperatures are typical, rising above 50% if conditions are hotter than average. The final at MetLife Stadium in New Jersey kicks off at 3pm, when the probability of extreme heat is about 30% in a typical summer and 55% in a hot one.<\/p>\n Those estimates may even turn out to be conservative. Heatwaves are becoming more frequent and intense globally. The 2021 western North America heatwave<\/a> shattered records by more than 4\u00b0C in some locations. A similarly extreme event during the World Cup could push lower-risk cities such as Seattle, Toronto and Vancouver into dangerous territory, while prolonging extreme evening heat in more vulnerable venues such as Miami, Kansas City and Philadelphia.<\/p>\n And even air-conditioned stadiums do not remove the wider public-health risk.<\/p>\n In the hottest cities such as Dallas and Houston, indoor venues may protect players and match officials during the game itself. But tens of thousands of spectators will still spend hours travelling, queueing and celebrating in dangerous outdoor heat. Many fans are older, less physically fit than elite athletes, dehydrated from alcohol consumption, or arriving from cooler climates with little acclimatisation.<\/p>\n The risk therefore extends well beyond the pitch.<\/p>\n Yet Fifa\u2019s current heat policy<\/a> remains limited. All matches will have three-minute hydration breaks<\/a> midway through each half, but the threshold for stronger action remains exceedingly high. Current Fifa guidance only mandates additional precautions at a WBGT of 32\u00b0C.<\/p>\n That figure has alarmed scientists and medical experts who have sent an open letter<\/a> urging Fifa to strengthen its heat protections before the tournament begins. Their recommendations include doubling the time for cooling breaks to six minutes, lowering the WBGT threshold for intervention and introducing clearer rules for delaying or postponing matches in dangerous conditions. <\/p>\n It is possible matches could be delayed or postponed if WBGTs exceed 32\u00b0C. This would be a decision for Fifa \u2013 and is something they have never done before. It is worth noting that the 32\u00b0C threshold is also considerably above levels many experts consider dangerous.<\/p>\n![\"A](\"https:\/\/images.theconversation.com\/files\/737677\/original\/file-20260522-57-i029vo.jpg?ixlib=rb-4.1.0&q=45&auto=format&w=754&fit=clip\")
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\n <\/figcaption><\/figure>\nPossible solutions?<\/h2>\n
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