Heat has become the weather risk that city governments fear most. Unlike a storm, a heatwave arrives quietly, and its victims — disproportionately the elderly, the poor and outdoor workers — often die indoors, out of sight of the cameras. After successive record-breaking summers, cities on every continent are rewriting their playbooks, treating extreme heat less like weather and more like a recurring disaster to be engineered against, as our reporting in the news section has tracked through the season.
The physics of cities works against them. Asphalt and concrete absorb heat by day and release it slowly at night, a phenomenon known as the urban heat island effect, which can leave dense neighbourhoods several degrees hotter than surrounding countryside — with the gap widest at night, when the human body most needs relief. The poorest districts, with the least tree cover and the worst-insulated housing, are almost always the hottest.
Shade, Water and Cooler Surfaces
The first line of defence is physical. Tree-planting programmes are being targeted by heat maps rather than aesthetics, concentrating canopy in the hottest postcodes. Cities are unsealing pavements, adding pocket parks and green corridors, and painting roofs and roads with reflective coatings that measurably lower surface temperatures. Public fountains, misting stations and extended hours at pools and libraries convert existing assets into a cooling network.
The networks matter because air conditioning, while lifesaving, cannot be the whole answer: it is unaffordable for many households, strains power grids at exactly the peak moments, and dumps waste heat into the streets. Guidance from the World Health Organization stresses layered protection — cool spaces, hydration, check-ins on vulnerable people — alongside building standards that keep indoor temperatures survivable during blackouts.
Warning Systems and New Officials
Forecasting has improved to the point where dangerous heat can be predicted days ahead, and cities are building response systems around those warnings: named heatwaves to raise public attention, text alerts, door-knocking campaigns in at-risk housing, and work-rest rules for outdoor labour triggered by temperature thresholds rather than discretion. Several cities have appointed chief heat officers — a job title that did not exist a decade ago — to coordinate across departments that previously treated heat as nobody’s responsibility. Coalitions such as C40 Cities now exist largely to spread these playbooks between mayors.
Preparedness also extends to the compound events that accompany heat: wildfire smoke drifting over cities, drought restrictions, and storms that follow heat domes. Emergency plans increasingly rehearse these combinations together rather than separately.
The Long Work of Redesign
Emergency measures buy time; design decides outcomes. Building codes are being rewritten for shading, ventilation and heat-resistant materials; planning rules protect airflow corridors; and insurers and lenders are beginning to price heat risk into property, which may move markets faster than regulation. Retrofitting the existing city — its tower blocks, schools and care homes — is the largest and slowest task, and the one on which the next decades of heat will be judged.
What has changed most is the framing. Heat was once treated as an act of God to be endured. Cities now treat it as a foreseeable, unevenly distributed risk that good preparation can blunt — a shift visible across lifestyle and community reporting as neighbourhoods organise their own shade, water and welfare checks. The heat is still coming. The question cities are answering is whether anyone has to face it alone and unprepared.
