World Cup Faces Dangerous Heat as Players' Union Threshold Breached

The World Cup has barely drawn breath, and already the thermometer is dictating the terms.

A Guardian analysis of the opening round of fixtures – the first 24 matches, one per team – shows that two games were played in heat so intense that the global players’ union Fifpro has previously said it should trigger delay or postponement. Four more were staged in cities above that same danger line, with only stadium air conditioning keeping conditions remotely manageable.

This is the tournament Fifa was warned about: a World Cup scattered across a roasting North American summer, forecast to be the hottest in the competition’s history.

Saudi Arabia v Uruguay tops the danger list

The most extreme conditions so far came in Miami, where Saudi Arabia faced Uruguay. Despite an evening kick-off, the match was played in a wet-bulb temperature of 28C (82F) or higher – the level at which Fifpro has argued that games should be pushed back or called off.

Sweden v Tunisia in Monterrey, also an evening game and also played in a stadium without air conditioning, ranked as the second most severe in the analysis.

Wet-bulb temperature is not a familiar number on a broadcast graphic, but it is the figure that matters. It blends air temperature, humidity and cloud cover into a single measure of how well the human body can cool itself through sweating. Once that balance tips, sweat stops evaporating properly, the body overheats quickly and the risk escalates from fatigue to illness, even death.

Fifpro has previously been clear: 28C wet-bulb should be a red line. Asked to respond to these findings at this World Cup, the union declined to comment.

Six games already over the line

Using data from government weather agencies in the US and UK, and a wet-bulb formula employed by authorities in countries including Australia and Canada, the analysis found that six of the first 24 matches took place where wet-bulb temperatures hit 28C or above.

Those games were:

• Germany v Curacao in Houston
• Saudi Arabia v Uruguay in Miami
• Portugal v DR Congo in Houston
• Netherlands v Japan in Dallas
• England v Croatia in Dallas
• And a second match in Dallas, again England v Croatia, where the city’s conditions were among the fiercest yet

Houston and Dallas have one crucial difference from Miami and Monterrey: air-conditioned stadiums. In Dallas, when England met Croatia on Wednesday, the external wet-bulb temperature climbed to nearly 35C (95F). Inside, the stadium systems dragged that down to around 22C (71F), a gulf that may well have spared players and officials from serious heat stress.

Fans and workers left in the furnace

Record-breaking temperatures around some venues have already taken a visible toll. Supporters have been left to wilt in shadeless concourses and open approaches to stadiums. Stadium workers – many of them on their feet for hours, hauling equipment or staffing concessions long before kick-off – face conditions that public health experts describe as potentially hazardous.

On the eve of the tournament, a group of heat and public health specialists sent an open letter urging Fifa to go further on protections. They pointed directly to Fifpro’s 28C wet-bulb benchmark and called for games to be postponed or cancelled once that threshold is breached.

Robbie Parks, an environmental epidemiologist at Columbia University and one of the signatories, underlined how misleading standard readings can be.

“Temperatures are often taken from shaded areas and if players are in direct sun, it can be double figures more than the temperature readings,” he said. Standing in the sun, he warned, can be dangerous even at lower levels – above 23C (73F) or 25C (77F) he would already be concerned for older adults exposed for more than a few minutes.

For players, Parks acknowledged that air conditioning, later kick-offs and water breaks will help. For fans and staff, he argued, the response has to be broader. “Shade is super important and hydration is super important,” he said. Allowing people to bring their own water, installing misting systems for evaporative cooling – these are the basics he wants to see.

His eye is already on the final in New Jersey, a venue without a roof. “That stadium isn’t covered which makes me worry,” he said. “But I’d hope Fifa will learn the best way to deal with that by then.”

Fifa’s thresholds under scrutiny

Fifa’s current guidelines state that cooling breaks should be introduced when games are played at 32C (89F) or above. In practice at this World Cup, drinks breaks have been ordered at lower temperatures, a tacit acknowledgement of the intensity of the conditions.

Decisions to delay or suspend games remain at the discretion of competition organisers. So far, despite wet-bulb readings pushing past the level highlighted by Fifpro and health experts, matches have gone ahead.

Conscious of the heat before a ball was kicked, Fifa agreed a “tiered mitigation model” for extreme temperatures. Different thresholds trigger different interventions. For players, that means mandatory hydration breaks, ready access to water and electrolyte drinks, and an array of cooling tools: ice, cold towels, fans, mist and shade.

For spectators, elevated temperatures are supposed to prompt “additional cooling capacity” at stadiums: more shaded areas, misting systems, cooling buses and expanded water distribution.

A new medical protocol has also been introduced specifically for heat exertion, with cooling bags set to be used at a World Cup for the first time.

A Fifa spokesperson said the governing body is “committed to protecting the health and safety of all players, referees, fans, volunteers and staff”. Meteorologists have been stationed at match venues to help prepare for extreme weather, with tournament planning described as involving “close coordination” with host city organisers, stadium authorities and national agencies.

Fifa says it will continue to track conditions in real time, using wet-bulb globe temperature and heat index surveillance, and stands ready to activate contingency plans if extreme weather hits.

A climate reality the World Cup cannot outrun

All of this sits inside a wider, harsher backdrop. Extreme heat is already the deadliest climate-related hazard on the planet, claiming more lives each year than hurricanes, floods and wildfires combined. This World Cup will add to the problem it is trying to manage.

More than 100 matches, long-haul travel between 16 venues and the vast logistics footprint of a modern tournament are expected to generate an estimated 7.8m tonnes of greenhouse gases, according to figures from Greenly, a global carbon accounting platform. That is roughly double the emissions attributed to the previous World Cup in Qatar.

The spectacle rolls on, cooled by air-conditioned arenas and punctuated by drinks breaks. Outside, the mercury keeps climbing. The question now is not whether this World Cup can be played in such conditions – it clearly can – but how long football can afford to treat heat like this as just another scheduling problem.