It doesn’t sweep away everything in its path like a hurricane. It doesn’t leave a trail of instant destruction like a speeding train crash. On the contrary, the silent, dispersed and extreme heat claims more victims than we think and puts millions of workers at risk.
In Latin America and the Caribbean, an estimated 48,000 older adults died prematurely from causes related to extreme heat in 2023 alone. Over the past two decades, heat-related mortality has increased by 140% in the region.
Although those most threatened are people with chronic problems and weak organs, extreme heat puts at risk millions of workers who, under a scorching sun, see their health and productive capacity undermined, transforming every working day into a battle for their survival.
Seven out of ten workers in the region, especially in the construction, agriculture and informal urban work sectors, are exposed to these heatwaves. It is predicted that losses from urban heating could reach 5% of gross domestic product (GDP) in major cities in the coming decades if action is not taken quickly.
In this context, the World Bank report Uninhabitable – Facing extreme heat in Latin America and the Caribbean highlights the risk for a region where eight in ten people live in increasingly hotter cities. At the same time, the study offers solutions that will allow cities and their inhabitants to adapt to this climate reality that is expected to be even more difficult in the future.
scorching heat
The region’s cities are getting hotter. Since 1950, the average temperature in cities has increased by up to 1.5°C. And the last decade has been the warmest on record.
Temperatures are rising in all climate zones of the region. Daily maximum temperatures in urban areas are projected to increase by 2.3-2.7°C by the end of the century. The Caribbean and Amazon will be most affected by this increase.
Cities in Latin America and the Caribbean are projected to face, on average, 36-69 more hot days by mid-century and 66-116 more days by the end of the century. In 2024, Mexico City, for example, experienced the six hottest days in its history. In Argentina, in the same year, heat waves saw days of up to 45°C
Added to high temperatures is a key factor that aggravates the risks: the urban heat island effect. Built-up areas absorb and retain heat, and the temperature in high-density areas with little green space can be several degrees warmer.
Infrastructure and services are also not prepared for a red thermometer: low quality housing, especially those inhabited by people with lower incomes, neighborhoods with little vegetation; Power grids that collapse due to high demand for cooling and transportation systems were not created to withstand such high temperatures. Schools are forced to close so as not to put students at risk, but at the same time they generate a large cost: the loss of learning.
What can cities do?
Cities across Latin America and the Caribbean have adopted a variety of measures to reduce the impacts of extreme heat. One starting point is to cool cities with nature-based solutions. For example, adding green spaces and tree cover.
In Medellín, green corridors have been created along 18 urban streets and 12 waterways; In Mexico City an important viaduct has become a vertical garden with more than a thousand pillars and green stripes. And in Costa Rica, connected strips of green space are being created in dense urban areas. These projects, in addition to helping to cope with the heat, make cities more liveable.
Improvements in urban design and form are also helping. The Barrios Verticales project in Bogotá, Colombia, reuses spaces previously intended exclusively for cars to convert them into pedestrian spaces. To do this, they are improving green areas and integrating vegetation into the already built environment, thus reducing overheating of the areas.
Other strategies have to do with the passive cooling of homes and buildings: from taking into account the orientation of the sites with respect to the direction of the prevailing winds to the use of cold roofs, i.e. those that avoid heavy materials so as not to absorb heat.
Saving lives and protecting jobs during extreme heat events also requires putting in place early warning systems. The World Bank report highlights that, according to UN data, it is estimated that expanding these systems could save the lives of 98,000 people in 77 countries alone.
Improve adaptive social protection systems to deliver aid quickly or innovative mechanisms such as microinsurance that enable automatic payments when heat waves occur.
Putting emphasis on the institutional agenda, integrating this approach into strategies, operations and budgets is fundamental to respond to a threat that requires global and systematic responses.
