Paris 2024 aims to be the most sustainable and environmentally friendly Games in history, but that goal could be threatened by dissatisfaction from many athletes and fears of high temperatures forecast for the European summer.

The Olympic Village has been designed without air conditioning in the athletes' areas, instead using natural resources and an underground cooling system, similar to that of the Louvre Museum, to mitigate the expected sweltering temperatures during the 33rd Olympic Games.

The Village's water-based cooling system will draw water from the River Seine to cool power plants. From there, the chilled water will be circulated through the buildings' pipes, significantly reducing the overall temperature of the buildings. However, many athletes believe this will not be enough to achieve the ideal temperature for crucial rest periods.

The organisers claim that the Village will produce around half the carbon emissions of a conventional building, thanks to the use of low-carbon timber and concrete structures and a renewable geothermal heating system. The Village took seven years to build and cost around $2 billion, according to the Paris 2024 organisers.

With this in mind, athletes who need proper rest, training and nutrition to perform at their best are planning to bring their own air conditioners to the Paris Olympic Village.

Although it is too early to predict the weather when the Games open in Paris on 26 July, Europe experienced record temperatures last summer and historically the French capital has seen temperatures above 35°C for at least 7 to 10 days between the end of July and August.

The International Olympic Committee (IOC) has promised that these Games will be the most sustainable in history, outlining a plan to "halve the carbon footprint of the Games compared to previous Games". This plan includes installing a water-based cooling system in the Olympic Village instead of air conditioning, ensuring the site has a 30% lower carbon footprint than a traditional construction project. However, this plan does not guarantee the ideal temperature for athletes to rest when temperatures soar.

In response, many countries are planning to use portable air conditioning in at least some of their athletes' rooms on hot days —a move that contradicts the IOC's sustainability claims. The USA, Great Britain, Denmark and Italy, among others, are the main countries considering this decision, which could be adopted by others due to its relatively low cost (between €400 and €500) and ease of transport and installation.

The Australian Olympic Committee's decision to install air conditioning in all of its athletes' rooms is "strategic for high performance" and will help them sleep, Anna Meares —head of the country's delegation— told The Guardian.

Alexandra Palli, the Greek Olympic Committee's president for environmental sustainability, confirmed they would do the same, making it unlikely they would meet their target of halving their carbon footprint.

"Despite outside temperatures of 41°C, we had 28°C in most of these rooms," explained Laurent Michaud, director of the Olympic Village, during the presentation last February, noting that air conditioning would only be necessary during extreme heat waves, as indoor temperatures rarely exceed 26°C.

In a clear show of support, French President Emmanuel Macron said at the official opening: "This is an example of the city of the future. Here we see the buildings that will be built in 2040, capable of withstanding the climatic conditions of 2050, both cold and heat," endorsing not only the system used in the Olympic Village but also its role as a model for the future.