Switzerland is built for winter. Almost all buildings are equipped with heating systems and were designed to maximise exposure to the sun’s rays in colder months.

However, due to climate change, winters are getting milder and heatwaves are growing more frequent and intense. Switzerland is meanwhile among the countries where temperatures are rising fastest. Together with the United Kingdom, it could be set to experience one of the sharpest relative increases in the number of days of uncomfortably high temperatures.

As temperatures rise, the use air conditioning is also on the increase. This summer, sales of portable air conditioners and fans reached record levels in Switzerland. Cooling technologies improve comfort and reduce heat-related deaths, but can also increase pressure on electricity grids, contribute to the urban heat island effect, and raise greenhouse gas emissions.

“Cooling is becoming an increasingly important challenge for both buildings and the electricity system,” Urs-Peter Menti, professor and co-director of the Institute of Building Technology and Energy at the Lucerne University of Applied Sciences and Arts, told Swissinfo.

This trend extends well beyond Switzerland. Electricity demand for cooling is rising sharply worldwide. In European Union countries, energy consumption for cooling doubled between 2018 and 2024. There has also been significant growth in the US and across Asia and the Middle East. Switzerland is one of many countries trying to figure out how to avoid the hazards of a warming planet without contributing to that warming through additional emissions.