UdL's cooling vests: La Roja's secret weapon

While in Lleida, Catalan independence activists boycott Spanish athletes like Saúl Craviotto as local institutions look the other way, the University of Lleida (UdL) has become the technological brain enabling the Spanish National Football Team to compete at the highest level in the 2026 World Cup. The cooling vests designed by Professor Luisa F. Cabeza and her GREIA team (Energy and Artificial Intelligence Research Group) reduce the skin temperature of footballers by up to 13 degrees—a breakthrough already used by fourteen national teams at the World Cup. This contrast highlights the political schizophrenia of a Lleida that generates world-class innovation for Spain, while its institutions snub it for sectarian reasons.

Twenty Years of Research That Changed the Game

The origins of this technology are neither improvised nor a recent flash of inspiration. Professor Luisa F. Cabeza, from the Department of Industrial Engineering and Building at the UdL’s Escola Politècnica Superior (EPS) and a specialist in thermal materials, began working on the design of garments with phase change materials (PCM) more than two decades ago. “We started working over twenty years ago on designing clothing items, like vests, with phase change material,” the researcher explains in statements reported by the newspaper Segre.

Collaboration with Sweden’s KTH Royal Institute of Technology was key to perfecting the system. The physical principle is simple yet revolutionary: PCMs absorb heat from the human body by transitioning from solid to liquid, achieving drops of up to 13 degrees on the skin and up to half a degree inside the body, without cooling the muscles. “PCMs allow for energy balances when they change from solid to liquid, or vice versa. These are changes that require a lot of energy,” Cabeza notes. “Melting a liter of ice requires 80 times more energy than heating that water by 10 degrees.”

The Real Impact on Football Performance

Accumulated heat in the body during a high-intensity match is no minor issue. According to Nazaret Ruiz, a researcher at the University of Cádiz, heat accelerates fatigue, reduces the ability to repeat efforts, and directly affects decision-making. In a sport where margins are razor-thin and games are decided in the final minutes, keeping a cool head—literally—can make the difference between winning and losing.

The mechanism of the vests is precise: the vest’s gel contacts the players’ bodies at 24 degrees when they are typically at 36 degrees, activating the energy absorption balance as the material liquefies. This allows footballers to maintain an optimal body temperature during breaks, between the first and second halves, or in stoppage time. It’s no coincidence that up to fourteen teams—the World Cup finalists and twelve others—are using these cooling vests in the 2026 tournament.

The Contrast with Political Lleida

While the UdL proves that Lleida’s talent can compete at the highest global level, the local political reality paints a very different picture. Catalan independence supporters, who control most local and provincial institutions, have boycotted Spanish athletes like Saúl Craviotto, an Olympic medalist from Lleida, simply for asserting his Spanish identity. Instead of proudly showcasing that a researcher from Lleida designed the “secret weapon” of La Roja, institutions look the other way or downplay the achievement.

This contrast is significant. While local institutions controlled by independence supporters devote efforts to promoting their doctrines and boycotting Spanish national symbols, the UdL—a public Catalan institution dependent on the regional government—generates innovation that directly benefits the Spanish National Team. The schizophrenia is evident: Spain is snubbed politically while being provided the technology that could win it a World Cup.

Lleida’s Talent vs. Sectarianism

The story of these cooling vests is the story of what Lleida could be if it stopped navel-gazing. Professor Luisa F. Cabeza and her GREIA team have been researching for over twenty years without making noise, without chasing headlines, but with results that speak for themselves. They don’t need banners or independence proclamations to put Lleida on the world map; they do it with science, hard work, and excellence.

While Catalan independence efforts insist on dividing, confronting, and boycotting, the UdL shows that the path is different: collaborate, innovate, and compete. The cooling vests of La Roja are not just a piece of technical gear; they are a symbol of what Lleida can contribute to Spain when it sets aside sectarianism and focuses on what truly matters: talent, effort, and the ability to generate useful knowledge for society.

A Reflection on the Future

The 2026 World Cup will pass, but the technology developed by the UdL has applications far beyond football. Phase change materials can be used in the textile industry, construction, medicine, or protecting workers exposed to high temperatures. The research of Luisa F. Cabeza and her team is a strategic asset for Lleida, Catalonia, and Spain.

The question Lleida’s citizens should ask themselves is: what do we want to be? A city that boycotts its own athletes for political reasons, or a city that prides itself on its university being the technological brain of the Spanish National Team? The answer should be obvious, but independence sectarianism complicates it. Meanwhile, the UdL’s cooling vests will keep cooling La Roja’s footballers, proving that Lleida’s talent knows no borders or flags. And that, when allowed to work, it can go where sectarianism never will.