A new report has revealed the shocking impact of extreme heat on poor women workers worldwide. According to the report, titled 'Counting the Cost of Heat: The Case for Urgent Solutions for Cities', extreme heat is costing informal sector women workers an estimated $57 billion in earnings each year.
The report, which was released today, analyzed four cities with different climates: Ahmedabad in India, Bangkok in Thailand, Monterrey in Mexico, and Freetown in Sierra Leone. It found that extreme heat already drains as much as 4 to 8% of city GDP in an average year and claims more than 1,000 lives.
The report's central message is one of opportunity, highlighting that the solutions exist and are affordable. The authors argue that a representative portfolio of low-cost interventions, including Heat Response Plans, urban green space, cool roofs, labor protections, and heat insurance, could reduce heat-related mortality by more than 36% by 2050 in the cities analyzed.
'Extreme heat is draining growth, health, and equality, not a distant climate risk,' said Kathy Baughman McLeod, CEO of HERA. 'The evidence in this report is unambiguous. Heat is taking a major toll on the women most exposed and least able to escape it, and it is quietly scarring the economies of cities that can least afford the loss.'
Heat accounts for a larger share of women's mortality than men's, up to 20%, driven by a combination of physiological factors and the social and economic conditions that increase women's exposure and reduce their capacity to adapt. Women reinvest up to 90% of their income back into their families and communities, so when heat cuts their earnings, spending on children's education, nutrition, and healthcare falls with it.
The damage ripples outward. In Bangkok, extreme heat reduces women's annual spending on their children by $500. Heat-driven productivity losses reduce the city's GDP by an average of 4% a year, the equivalent of the city government's entire budget, and as much as 8% in an unusually hot year.
In Freetown, extreme heat raises the average household debt-to-income ratio by 3% annually, crowding out investment in education and entrepreneurship. In Monterrey alone, heat-related pre-term births are expected to more than triple over the next 25 years.
Across the cities analyzed, working women are consistently more likely than working men to be employed informally, reaching as high as 91% of employed women in Freetown (compared to 83% of employed men).
The report highlights that rising nighttime temperatures, which in many cities are climbing faster than daytime highs, are a critical and often overlooked driver of illness and death. Hot nights deny the body any respite, and together with compound heatwaves they account for 85% of heat-related mortality.
The risk falls hardest on lower-income residents living in homes built from heat-trapping materials like corrugated iron and tin, a reality sharply felt in Freetown.
Despite the scale of the threat, the report emphasizes that the solutions are affordable and exist. Heat Response Plans generate returns of between 12 and 90 times their cost, making them among the most cost-effective public health investments available.
In response to the report, Kathy Baughman McLeod of HERA urged urgent action, saying, 'We have the knowledge and the tools to tackle this. It's time for cities to take action to protect their most vulnerable residents from the impacts of extreme heat.'