Designing cities for a hotter future

With extreme heat events becoming more frequent, longer lasting, and more dangerous, designing resilient cities will depend on creating spaces that remain usable and protective even when temperatures rise and power grids strain. In that context, designing for thermal resilience through microclimate planning – the practice of shaping neighborhoods and landscapes to manage localized weather conditions – has become an increasingly important design requirement.

The scale of the challenge is already visible in cities where rising temperatures are placing increasing pressure on public health systems, energy infrastructure, and everyday urban life. New York City, for example, illustrates how quickly this vulnerability becomes a public health threat. A five-year review of syndromic surveillance data from 2017 to 2021 recorded more than 2,900 heat-related emergency department visits citywide, 76 days when the heat index surpassed 95°F, and 21 days when it exceeded 100°F. The most extreme episode in that period, July 21, 2019, when the heat index reached 107°F, sent 111 people to emergency rooms in a single 24-hour span.

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The risk compounds because electricity demand spikes alongside heat, straining power grids precisely when cooling is most critical. When thermal comfort depends entirely on continuous electricity, the failure of a single system becomes a public health emergency rather than a simple inconvenience, and the consequences fall disproportionately on outdoor workers, older adults, children, people with disabilities, and unhoused populations, who are often the least likely to have reliable access to cooled environments. The greatest risk, then, is not extreme heat alone, but the simultaneous failure of the built environment and the infrastructure that supports it.

This reality changes what should be expected of design. Buildings and public spaces can no longer be considered successful simply because they perform well under normal operating conditions; they must also remain safe and habitable when the systems they depend on are disrupted. Thermal resilience must be embedded within the built environment through strategies such as orientation, shading, natural ventilation, material selection, and low-energy cooling technologies, so that thermal conditions deteriorate gradually rather than catastrophically during grid failure or extreme weather.

Retrofitting existing buildings and updating codes to reflect this shift will take decades, but cities do not need to wait to begin reducing heat risk. The nearer-term opportunity lies in the public spaces where heat exposure is already greatest: bus stops, schoolyards, construction sites, parks, and plazas. Deploying modular cooling infrastructure in these spaces embeds thermal resilience directly into public infrastructure, rather than treating it as a property of architecture alone, making everyday movement through the city safer during periods of extreme heat.

Singapore’s 21.5-kilometer North-South Corridor shows how microclimate planning and thermal resilience can be embedded at the scale of an entire city. Henning Larsen partnered with Ramboll, Cistri, Gehl, Participate in Design, Camphora, URBAN+ and LOPELAB, to reimagine a major transportation corridor as a multimodal landscape where mobility, community, and nature reinforce one another. The masterplan is organized into four character zones, including the Ecological Loop and the People’s Wellness Corridor. The design prioritizes walking, cycling, and public transit while weaving shaded tree canopy, green corridors, and biodiversity into the streetscape. Together, these strategies are designed to reduce heat exposure for thousands of daily users and demonstrate how thermal resilience can become an everyday feature of urban infrastructure rather than an isolated response to extreme events.