Summer Heat: a challenge of culture as well as technology

Increasingly frequent heatwaves are forcing us to radically rethink the way we design and inhabit our urban spaces. Speaking to the German radio station WDR 3, Sascha Roesler, Associate Professor of Urbanisation Theory at USI Academy of Architecture, urges us to view air conditioning not merely as a technical matter, but as a "cultural practice" that concerns society as a whole.

While air conditioning is taken for granted as the standard in many parts of the world, summer cooling remains a controversial topic in Central Europe—especially in Switzerland and Germany—primarily due to cultural and energy-related concerns, often perceived as a waste of energy or a source of ailments. According to Sascha Roesler, this scepticism has deep historical roots: for generations, we have designed buildings almost exclusively around winter heating requirements. Today, adapting to a changed summer climate reality demands an equally profound cultural shift, the assimilation of which will inevitably be gradual.

From private air conditioning to a collective cooling strategy
Projections indicate that, by the end of the century, Swiss and German cities will experience climates similar to that of northern Spain. "We can no longer afford to leave this problem solely to individual initiative or to turn it into an ideological debate," Roesler explains. While the installation of single air-conditioning units by private individuals offers an immediate response to the emergency, the real challenge lies in conceiving cooling as a public and collective responsibility, much as was historically done with central or district heating networks. Adapting to global warming cannot be limited to open spaces and public squares; it must also integrate the thermal infrastructure inside buildings, starting with critical facilities such as hospitals.

What we can learn from global cities
According to Professor Roesler's research, studies conducted in urban environments such as Singapore and Chongqing highlight the risks of relying solely on private air conditioning, which can ultimately undermine bioclimatic design and natural ventilation strategies. For Central Europe, Roesler proposes an approach rooted in the region's strong democratic tradition: collectively defining which energy and cooling systems are necessary and how to ensure equitable access to them. In the long term, the reduced demand for winter heating will help offset summer cooling consumption in the overall annual energy balance.

Solutions for the future of our cities
Changing the way we construct buildings takes decades. Still, the devaluation of urban centres due to urban heat islands is already a tangible risk for investors and property owners. It is therefore of paramount importance to reconsider the use of traditional materials, limit the use of large glazed façades, and implement advanced shading systems. In the short term, cities could deploy practical and accessible solutions, such as strategically opening already air-conditioned public spaces—such as libraries, universities, and public transport—and turning them into genuine "thermal oases" that offer respite during heatwaves.