For the first time mandatory, whatever the weather
At this World Cup, hydration breaks are mandatory in every match for the first time. The referee stops play midway through each half, around the 23rd and 68th minute, for a three-minute break. This happens regardless of the temperature, the kick-off time or whether the stadium has air conditioning. The match clock keeps running, and the time is added on as stoppage time at the end of each half.
This is new. Until now, hydration breaks only occurred in extreme heat, around the 30th and 75th minutes, when a heat measure exceeded a certain threshold. Following a court ruling, FIFA introduced them at the 2014 World Cup in Brazil. They were trialled again at the 2025 Club World Cup.
Why are there two hydration breaks as standard?
Ten of the World Cup’s sixteen venues are classed as risk areas for “extremely high temperatures”. The three host cities of the Dutch national team, Dallas, Houston and Kansas City, all sit within that zone. In Dallas and Houston, stadium roofs still offer some protection. But the match against Tunisia in Kansas City is played in the uncovered Arrowhead Stadium, where the heat can rise sharply.
FIFA also gives three further reasons: player health, equal conditions for all teams, and predictability. A fixed break is also an extra fixed advertising slot, which suits broadcasters well. That last point in particular drew criticism.
Temperature only tells half the story
Yet heat is the real reason the rule exists. And measuring heat is more complex than reading a thermometer. Carolina Pereira Marghidan, a PhD researcher at the University of Twente and the KNMI, is an expert on heat warning thresholds. “Whether a player overheats depends on more than temperature alone,” Carolina explains. “Humidity, wind and the sun matter just as much for how hard the body has to work. And in elite sport, the amount of physical effort certainly plays a role too.”
That is why sports bodies look at the WBGT, the Wet Bulb Globe Temperature. This measure combines temperature, humidity, wind and solar radiation into a single figure. It has been used in sport and in workplaces for decades to judge when exertion becomes dangerous. A WBGT of 23 degrees sounds mild, but already amounts to considerable heat stress.
On 2 June, the Netherlands gained a new, public-friendly measure for heat. The KNMI app now shows hittekracht (roughly: ‘heat force’): a scale from 0 to 10 based on the WBGT. Carolina developed the scientific underpinning and underlying methodology of that scale. “This turns an abstract number into something people can get a feel for,” she says.
The old threshold sat at the maximum
The old rule had a weak spot. The automatic hydration breaks only kicked in at a WBGT of 32 degrees. On the Dutch hittekracht scale, that is a 10, the highest value. “In De Bilt, a hittekracht of 10 has occurred for just four hours over the past thirty years,” Carolina says. “A threshold at that level means you rarely step in.”
The players’ union FIFPRO sets the limit far lower. It recommends hydration breaks from a WBGT of 26 degrees (hittekracht 7) and calls play unsafe above a WBGT of 28 degrees (hittekracht 8). Researchers at World Weather Attribution calculated that around a quarter of the World Cup matches will exceed that danger level. That is almost double the figure for the previous World Cup in the United States, in 1994.
The mandatory breaks sidestep that debate. By scheduling them every time, no one has to negotiate over a threshold. Still, last month, twenty scientists warned in an open letter to FIFA that drinking alone is not enough. They argue, shade, cooling and later kick-off times do more against heat stress than a sip of water.
Noticeable from the home too
For the keen football fan at home, hittekracht makes the heat you feel visible. The same measure that decides whether players can compete safely is now in your weather app. The next time the players reach for their bottles, you will know what lies behind it. And when the next commercial break rolls around, you might just grab a glass of water yourself.
