As Europe swelters under ever more frequent and ferocious summer heatwaves, cities are scrambling to cool themselves down. In recent weeks, temperatures in Paris peaked at 42°C, prompting the French capital to issue its third red alert in as many years. Northern and central European city-dwellers, who once sought refuge from the sweltering summer heat on the coasts, are increasingly dealing with beachy weather on trains, in office buildings and at home.
As temperatures rise and the rate of urbanisation increases, the continent’s traditionally temperate cities are being forced to rethink how they design, build and live. For guidance, they might look to places that have long coped with blistering heat and done so by infusing ingenuity with local flare.
Ancient solutions for modern problems
According to Economist Enterprise research, sponsored by Zurich, more than half of surveyed city residents cite heatwaves/extreme temperatures as their primary physical-risk concern in the face of climate change. As energy costs are expected to rise over the next year and the demand for energy from AI and rapid urbanisation puts the prospect of “aircon for all” out of reach for many cash-strapped residents, solutions will need to be both climate- and budget-friendly.
Traditional architecture in hot regions offers a trove of passive cooling strategies. Take the courtyard house, ubiquitous in the Middle East and North Africa. These inward-facing structures, with shaded courtyards often filled with greenery and water, create microclimates that are significantly cooler than the surrounding environment. In Seville, a southern Spanish city often referred to as the frying pan of Europe, urban planners are adapting this model by integrating small inner-city green patios and water features into public buildings and schools that help residents cool down and escape the heat when temperatures inside provide no relief.
Another solution, one that comes from farther-away Iran, are badgirs, or windcatchers— structures designed to channel wind, increasing ventilation and cooling. They are a hallmark of Persian architecture that has been keeping the inhabitants of some of the country’s hottest cities like Yazd and Abarkuh cool for centuries now. And European cities should take note. A recent study modelled the impact of windcatchers in schools in 15 major European cities and found that they provide a feasible, cost-effective method to improve indoor air quality and cool classrooms for students.
Harnessing the power of paint
From the sun-scorched rooftops of Jaipur to the sun-bleached stone alleys of Palermo, one of the cheapest and most effective weapons in the fight against extreme heat is also the most unassuming: colour. Across the globe, cities are discovering that painting buildings and roads in pale, reflective hues can do more than brighten up a drab skyline—it can bounce sunlight back into the sky, dramatically reducing the heat absorbed by the built environment.
A University College London study, published in 2024, found that light-coloured “cool roofs” outperform green roofs, solar panels or street trees in lowering urban temperatures in cities. In Greece, where temperatures can reach 40°C and above, white houses have long been a staple of the local architecture. Farther east, a trial in Ahmedabad, India, is testing cool roofs in informal settlements by painting residential roofs white to combat urban-heat-island effects. Similar trials were conducted in Burkina Faso, which yielded positive results and provided an appealing, cost-effective method for keeping residents comfortable even in soaring temperatures.
The appeal of reflective coatings lies in their simplicity and scalability. As cities heat up, governments may find that the most potent adaptation tool is not a costly megaproject, but a fresh coat of paint.
Microgreenery for macroimpact
Vegetation is not merely decorative—it is functional infrastructure. Cities are beginning to adopt the 3-30-300 rule whereby residents are close to 3 trees, live in neighbourhoods with 30% tree cover and are 300 metres from a public park.
Singapore, a tropical metropolis, has woven greenery into its urban fabric with remarkable success. Its Gardens by the Bay project combines vast plant-filled domes with public cooling spaces. Vertical gardens adorn high-rises, and the city’s Park Connector Network ensures that greenery is never far away.
Europe is catching on. Vienna has created “cool streets”, where trees, misting systems and light-coloured pavements offer residents respite. In 2022, the city piloted mobile trees—trees in movable planters—that were relocated across the city based on heat forecasts. In Rotterdam, the “green roof” initiative has covered over 360,000 square metres with sedum, moss and grass, absorbing heat and reducing run-off during storms.
But Europe’s urban canopy is still sparse compared with cities like Singapore or Sydney, which have invested in ambitious tree-planting programmes with long-term cooling in mind. In European cities, the challenge will be space. Often centuries old, with narrow streets and tightly packed residential areas, these cities will need to get creative. Whether through pocket parks, canopied courtyards or vertical gardens, green spaces will need to be adapted to fit with existing infrastructure.
Adapt or swelter
Cool cities are not only a matter of infrastructure, but of governance, public buy-in and resilience planning. In the last iteration of the Resilient Cities Index in 2023, New York, Los Angeles and London topped the scales. But as challenges become more complex and political and social headwinds increase, cities from Berlin to Bangkok must be ready to weather the heat and adapt for the new urban century, taking lessons from warmer cities and building an identity around urban adaptation.
Adaptation won’t be driven solely by cutting-edge technology or grand masterplans. It will rely on the everyday, often invisible decisions made by local governments, architects, community groups and residents. It means reworking existing infrastructure in small ways, be it painting or planting, that can make a huge difference in how city-dwellers manage and live with an increasingly hot planet. It means borrowing and adapting design principles from cities long familiar with heat, and investing in approaches that are accessible, culturally sensitive and economically viable. In the end, the hottest cities may yield the coolest lessons for the new urban future.