How England Are Outsmarting the World Cup's Worst Enemy

Kansas City, on a Saturday afternoon in the third week of June, is a city of hard light and stored heat. By the time England trained there, the sun had already done its work on the pitches, on the metal barriers, on the camera platforms and on the long line of staff carrying water, medical bags and equipment across the site. The players worked in it. Thomas Tuchel, watching and directing, was running a quieter experiment of his own: BBC Football reported that England’s staff used cooling hoodies as part of their response to the heat, with the manager taking a noticeably different approach to staying cool while the session went on.^{T2 - BBC Football}

It is the kind of image a tournament produces by the dozen, a coach in unfamiliar kit under an American sky, and it is tempting to file it under theatre. It reads better as a small public window onto a much larger fact about the World Cup that begins this summer. The 2026 tournament will not be played in one climate. It will be played across a continent, in Mexico, the United States and Canada, across altitude and humidity and late-afternoon glare, between air-conditioned hotels and exposed training grounds and stadiums whose roofs and kick-off times will not lift the work of thermoregulation off the bodies of footballers.

England’s cooling plan, as BBC Football described it, begins with a garment, but the garment is only the visible part of the system.^{T2 - BBC Football} Heat management at a tournament is a chain. It starts before the players leave the hotel and runs through the warm-up, the first half, half-time, the second half, recovery, sleep, and the next training morning. It is not really a question of whether a footballer feels hot. It is a question of how quickly the body stores heat, how efficiently it sheds it, how much fluid and sodium it loses doing so, and how far a player’s decision-making survives when his body is sending blood to the skin at the same moment the match is demanding another acceleration, another press, another recovery run.

The science is not decoration. In the heat, core temperature rises as muscle work produces heat; the body answers with more skin blood flow and more sweat. That cools, but it costs. More blood at the surface means greater cardiovascular strain. Heavy sweating drains body mass through fluid loss, and if that fluid is not replaced well, plasma volume falls, heart rate climbs for the same running speed, and the sense of effort rises. Over a hundred metres this is a footnote. In a World Cup knockout match, after seventy minutes of transitions, it can be the gap between arriving early enough to close a passing lane and arriving just late enough to give away a foul.

Football is an awkward subject for the heat scientist because it refuses to behave like a laboratory. A midfielder does not run at one speed for ninety minutes. A winger walks, jogs, sprints, stops, jumps, accelerates again, then stands over a corner with the sun still on the back of his neck. A goalkeeper passes long stretches barely moving, then has to be explosive. A substitute may cool on the bench for an hour and then be sent into a game already bent out of shape by heat fatigue. So the useful question for England’s staff is not only how hot it is. It is which player, in which role, in which state of the match, is losing the ability to repeat the action that makes him worth picking.

Cooling garments answer one part of that. A hood or a vest can work in several ways depending on its design, by conduction from chilled material, by evaporation, or by phase-change inserts that absorb heat as they melt. The head, the neck and the upper torso are attractive targets because they shape thermal sensation as much as heat exchange. A player who feels cooler has not necessarily dropped his core temperature by much, but in football perception is its own currency. A footballer who feels less heat stress may hold a higher intensity through the warm-up, or walk into the opening phase of a match without the early weight of fatigue.

There is a less photogenic reason to cool the staff, too. Tournament football is run by people who stand in the heat for long spells in accreditation, communication kit and formal or semi-formal clothing. A coach does not cover eleven kilometres, but his work is cognitive. He is reading spacing, pressing triggers, the opposition’s rotations, the emotional temperature of his own players, the risk of injury. A hot, dehydrated technical-area is worse at exactly the kind of attention a knockout match asks for. Tuchel in cooling kit looks like a comfort measure. The staff member who is still thinking clearly in the 83rd minute is part of the performance environment all the same.

The second layer is acclimatisation, and this is where 2026 becomes an organisational problem rather than a shopping list. Heat acclimatisation is built by repeated exposure over days: sweat that starts earlier, sweats more efficiently, expanded plasma volume, a lower heart-rate response at a given workload, better retention of electrolytes. None of it is instant, and none of it lasts without continued exposure. For a national team shuttling between host cities, the balance is delicate. Too little heat leaves players underprepared; too much, too close to a match, leaves them tired for no return.

England’s staff will have to choose how much heat to train in, when to find shade, when to move indoors or drop the intensity, and what to do with the first days after they land in a new city. The old tournament instinct was to admire players for enduring the conditions. Modern performance departments are less sentimental about it. Endurance is worth something only if it leaves a footballer able to play. A session that proves toughness and empties a squad two days before kick-off is bad science and bad football in the same breath.

Hydration is the third layer, and it is the one most often misread, because the public version of it is just the bottle. Elite hydration is more individual than that. Players sweat at different rates and lose sodium at different concentrations; two footballers can finish the same session in the same conditions and need different recovery plans. Staff estimate sweat loss by weighing players before and after training, while watching urine markers, thirst, cramp history, gut tolerance and the player’s own habits. The aim is not to drink as much as possible. Overdrinking without enough sodium carries its own medical risk; underdrinking blunts performance and recovery. What they are after is controlled replacement, before, during and after the work.

Cold fluids and ice slurries have a place here. In some sports, pre-cooling with crushed-ice drinks has been used to lower thermal strain before exercise in the heat. In football the difficulty is timing. A player cannot carry a laboratory protocol into the tunnel. The drink has to settle in the stomach, fit the shape of the warm-up, leave room for carbohydrate, and not sit heavy during high-speed running. At half-time the window is smaller still, crowded with the team talk, the medical checks, the tactical changes, the kit, the emotional reset. A heat plan that cannot survive the dressing room is no plan at all.

The geography of 2026 will make simplicity harder. A match in a humid American city is not the same task as a match at altitude in Mexico. Humidity blunts sweating because evaporation slows. Altitude rewrites the oxygen problem. Travel rewrites sleep. Air conditioning, so useful for recovery, builds a daily rhythm in which players step from a chilled interior into outdoor heat with almost no transition between the two. This will be a tournament of thresholds: the hotel lobby to the bus, the bus to the training pitch, the shaded bench to the touchline, the warm-up to match tempo.

England are not the only ones thinking it through, and not the team for whom it carries the most novelty. Curacao, the smallest nation by population ever to reach a men’s World Cup, a Dutch-Caribbean diaspora squad of around 150,000 people’s worth of belonging, have arrived at this tournament with their own medical answer to the same continent. Their head of medical is Dr Suzanne Huurman, only the third woman to hold such a role in a men’s World Cup setup. The heat does not consult the size of the federation. The work of getting eleven footballers through it falls, everywhere, on the same kind of unglamorous staff.

This is where marginal gains stop being a slogan. A tournament match is rarely decided by a single cause; a missed chance carries technique and pressure and fatigue and pitch speed and the defender’s recovery run inside it. Heat management guarantees nothing. What it does is shrink the number of moments in which fatigue makes the decision for the player. It might leave a full-back one more overlap, a centre-back his concentration through one more set-piece, a substitute the ability to enter at match speed instead of spending his first five minutes finding the air.

England’s football culture tends to fold every tournament plan into an argument about destiny and burden and identity. The heat plan belongs somewhere more practical than that. It is the work of doctors, physiologists, analysts, kit staff, chefs, logistics managers and coaches, trying to keep professional athletes near their best in conditions that will not be neutral. The cooling hoodie is the photograph. The story is the spreadsheet behind it, the sweat test, the altered session, the electrolyte sachet, the shade structure, the player quietly told not to do one more run because the match is in forty-eight hours.

In Kansas City, under that Saturday sun, England’s staff were not solving the World Cup. They were rehearsing one of its central facts. This summer will ask footballers to manage the ball, the opponent and the climate in the same instant, and the teams that understand all three may find that the science has quietly become part of the scoreline.