Extreme heat is costing women informal workers an estimated $57 billion in lost earnings each year outside Europe and the US.
Without urgent climate and urban policy interventions, these losses could surge 44% by 2050.
This will deepen gendered economic inequality and harm families and city economies.
Extreme heat impacts women disproportionately, not just physically but also financially. The culumative health and economic impact of extreme heat are being felt the most by informal women workers across the world, according to a report presented at the ongoing London Climate Action Week 2026.
Women in the informal sector across the world (except Europe and the United States) lose $57 billion annually in earnings due to extreme heat, analysed researchers at Hera (formerly Climate Resilience for All). Without appropriate intervention, this loss was projected to rise by 44 per cent by 2050, driven by climate change, unsustainable urbanisation and population ageing.
This is particularly concerning because of the higher concentration of women in the informal workforce. Upto 91% of women workers were informal in Ahmedabad (India), Bangkok (Thailand), Monterrey (Mexico) and Freetown (Sierra Leone) — the four cities with different climatic and heat characteristics chosen for economic modelling. Many of these women make as little as $3 per day, the findings showed.
Thus, for a significant population of working women, extreme heat widens social and economic inequalities they already face.
The authors of the report also noted that while being more exposed to extreme heat, women, especially those in informal labour, have the least protection from its effects.
"Women are more vulnerable to heat through a combination of compounding factors, including physiological sensitivity (especially during pregnancy), economic insecurity (earning less income and holding fewer assets), a heavier burden of unpaid care, norms that restrict clothing and movement, greater risk of gender-based violence, and more limited access to cooling, healthcare, social protection and safe working conditions," they wrote in the report.
In Ahmedabad, women informal workers lose 7 per cent of their annual income because of extreme heat. Gitaben Rawal, a headloader from Ahmedabad, shares how the multiple layers of harms from heat — both outdoor and indoor — play out in her life:
These compounded socioeconomic challenges lead to a higher share of women's mortality from extreme heat, up to 20 per cent, they added.
The loss impacts a wider section of the society over a longer time-period as women reinvest up to 90 per cent of their incomes back into their families and communities, according to the report. "So when heat cuts their earnings, spending on children’s education, nutrition, and healthcare falls with it. In Bangkok, extreme heat reduces women’s annual spending on their children by $500."
The report, according to the authors, integrates climate projections, health and labour productivity modeling, gender-disaggregated economic analysis, and qualitative evidence from informal women workers, alongside city-specific case studies of those most affected. These include factors from how heat disrupts their sleep to how it spoils the wares they sell.
Heat-related damages accumulate into a substantial reduction in a city's gross domestic product (GDP) through loss in productivity. "In the cities analysed, women suffer heat-driven annual productivity losses ranging from about 3% in Monterrey to 11% in Bangkok," the researchers noted.
In Bangkok, heat-driven productivity losses were found to decrease the city’s GDP by an average of 4 per cent a year, they found. This is comparable to the city government’s entire budget.
The stress is felt at the household level through an increase in the debt-to-income ratio, shrinking fiscal space for education and entrepreneurship. "Because women already earn less than men — from 66% less in Freetown to 4% less in Bangkok — even modest productivity losses translate into a greater proportional hit to household income, leaving fewer resources to fall back on."
A substantial percentage of women engaged in informal labour also live in informal settlements built with heat-trapping materials and negligible cooling options. This makes it worse for their bodies that get no opportunity to cool down with rising nighttime temperatures.
The researchers also built a cost-benefit tool for assessing heat solutions. These include a foundational heat response plan of the city, urban green space, cool roofs, labour protections and heat insurance. In the cities studied, these measures were calculated to reduce heat-related mortality by more than 36 per cent by 2050.
In Delhi, for instance, where there are about 1.7 million women informal workers, a highly implementable intervention package can reap $415.9 million by 2050. The tool, which covers 11,408 cities globally, is aimed at improving city-level budget decisions.
During the peak of the May 2026 heatwave, the city's women outdoor workers Down To Earth spoke to shared experiences that validate these findings. Hawkers at Delhi's Lajpat Nagar market, for instance, described reduced daily window for earning and increased health cost due to extreme heat.