Spain’s latest training image from Chattanooga could be misread at a glance. The white panels over the shirt look like padded training bibs, but their purpose is not protection. It is temperature control, one of the less-visible calculations shaping the preparation for this tournament.
At the 2026 World Cup, Spain is already planning for more than Cape Verde, its opening opponent in Atlanta. Luis de la Fuente’s staff has brought adidas’ CLIMACOOL SYSTEM into training, a setup built around a cooling vest, an outer jacket, and an overshoe. The point is simple enough: lower the body’s heat load before the most demanding work begins.
The vest is the main piece. Inside it are freezable gel sections that warm slowly once the player puts it on, pulling heat away from the upper body, especially the chest, midsection and back.
The jacket is the retention layer, limiting warm air around the vest so the cold lasts longer. Adidas says the vest and jacket can reduce core body temperature by as much as 0.5°C, about 0.9°F, and skin temperature by 13°C, about 23.4°F. The overshoe is designed to sit over the boot and reduce foot temperature by 2°C, about 3.6°F, within seven minutes.
The advantage is not that a vest turns a player into a better sprinter. It gives the body a cooler starting point. In hot and humid conditions, sweat cools only as well as it can evaporate. When evaporation slows, perceived effort rises and recovery between high-intensity actions becomes harder to manage. Soccer-specific research on torso cooling has found lower physiological and perceptual strain in heat, while peak sprint performance was largely unchanged.
A tournament shaped by heat
FIFA has already built heat into the competition’s operating rhythm. Every match has a three-minute hydration break midway through each half, regardless of weather, with play stopped around the 22nd minute in both halves. World Weather Attribution has estimated that 26 games at this World Cup are expected to reach at least 26°C WBGT, a heat-stress measure that accounts for temperature, humidity, wind and solar radiation. Its analysis also expects five games to reach 28°C WBGT, a level FIFPRO guidance treats as unsafe for play.
Spain’s case is immediate. The squad’s final buildup included training at Baylor School in Chattanooga before the trip to Atlanta, where Spain is scheduled to open against Cape Verde.
Carlos Cruz, Spain’s physical trainer, has explained that the vests are being used to make recovery more efficient, reduce body temperature, delay fatigue and speed the next recovery window. The phrasing matters because this is not miracle technology. It is a narrow intervention for a narrow problem, body heat accumulating faster than the athlete can shed it.
The same project also shows how far supplier technology now reaches around tournament football. Adidas developed the system from cooling work originally built for Mercedes-AMG Petronas Formula 1 drivers, then adapted it through football-specific testing with clubs including Manchester United, Juventus and Arsenal. Adidas is already part of the tournament’s equipment story, from the official match ball to federation kits and now cooling equipment used before kickoff.
For Spain, the visual may be unusual, but the logic is clinical. A cooler torso before training can mean less thermal strain, a steadier recovery profile and a better chance of keeping technical decisions clean when the air is heavy. In a World Cup spread across June and July in North America, preparation is no longer only tactical or physical. It is thermal.
