Hidden in Plain Heat: Informal workers in India's heat resilience story

Summer heat On 27 April this year, the world's 50 hottest cities were in a single country: India, according to real-time rankings from the air-quality platform AQI. A single day's heat data may not imply much, but India's summers have been arriving earlier and lasting longer in recent years. This begs the question: are these cities prepared for the heat? India Has Built a Strong Heat Resilience Framework By most measures, India has emerged as a genuine leader in extreme heat resilience across the Global South, backed by concrete policy action and homegrown innovation. Since Ahmedabad became South Asia's first city with a Heat Action Plan (HAP) in 2013, more than 250 cities and districts across 23 states now operate HAPs, according to India's National Disaster Management Authority . Heat has also been institutionalised as a disaster. The Ministry of Home Affairs has officially recognised heatwaves as a natural calamity, unlocking national and state funds for heat resilience. India has also pioneered innovations in this space, from parametric heat insurance to cooling carts . Taken together, these measures cover much of the essential ground. Yet one significant gap remains. Informal Workers Remain the Biggest Gap As HAPs roll out across more cities, their solutions are not designed for the largest vulnerable group in India's workforce: the 90 per cent who are informally employed, according to the 2024 India Employment Report . Informal workers are often the most exposed to extreme heat yet have the least protection, since the heat safety regulations mandated in HAPs typically apply to formal employment and lack targeted action. An analysis of 37 HAPs by the Centre for Policy Research found that while most identify vulnerable groups, their proposed measures often do not address their specific needs. For instance, HAPs may recommend cooling equipment without addressing the affordability and electricity-access constraints that make these solutions out of reach for many informal workers. Climate research organisation Sustainable Futures Collaborative's nine-city study of HAP implementation found that short-term emergency measures such as water access are widespread. However, long-term interventions such as occupational cooling, insurance for lost work and infrastructure upgrades remain largely limited or poorly aligned. The costs are tangible. Heat-related kidney problems, combined with reduced ability to work during heatwaves, are estimated to cost India US$78 billion in lost wages, equivalent to 1.99 per cent of GDP in 2024 , according to a 2026 study by the International Institute for Environment and Development (IIED). Traditional Wisdom Can Offer Modern Solutions Bridging this design gap lies at the intersection of old and new: reviving traditional wisdom for a modern context and learning from international best practices on integrating the informal economy into heat planning. Clay pot air coolers, a traditional evaporative cooling technique, offer a practical, low-cost alternative to more energy-intensive cooling solutions. These traditional materials can also be scaled into modern architecture. An IIT Delhi team developed 'Terracool', a terracotta wall cooling system that reportedly cut indoor temperatures by up to 7°C. Protecting Workers Requires More Than Advisories Not every fix is physical. For example, in June 2026, New York City's mayor mandated heat illness guidance covering 'all workers, including, but not limited to, employees, independent contractors, gig workers, and day labourers', in languages commonly spoken by the city's workforce. It also enforces an existing but underused protection: delivery workers' right to use restaurant restrooms during deliveries, regardless of employer status. This prevents a negative behavioural pattern where, without paid breaks or reliable access to restrooms, workers intentionally limit their water intake, raising their risk of dehydration, kidney disease and urinary tract infections (UTIs). Address the Root Causes of Heat Vulnerability This behaviour is well documented in India, too. Some female street vendors surveyed by the global research network Women in Informal Employment: Globalizing and Organizing said they deliberately restrict their water intake because of a lack of safe and accessible toilets, trading the risk of dehydration for indignity or unavailability. An enforced right to restroom access, rather than a simple advisory to 'stay hydrated', would address the root cause of dehydration rather than just its symptom. Such measures point towards mandated protection with real consequences for inaction, something Indian worker unions have long called for. These can be complemented by India's own innovations, particularly parametric heat insurance, which directly addresses the fear of lost wages that keeps informal workers working through extreme heat. Make Heat Resilience an Economic Priority To deepen the inclusion of the informal economy in India's heat resilience efforts, the private sector has a role to play too, through philanthropies, cooling technology companies and public-private partnerships. Prioritising and including this largest segment of the workforce would yield real gains in productivity and economic resilience. But the measures to protect them need to be targeted, tracked and, if necessary, incentivised or required rather than left as advisories. (Curtis Chin is Senior Advisor, Global Markets at the Milken Institute.) (Ella Tan is ​​Associate Director, Policy & Programs at Milken Institute.) Views are personal, and do not represent the stand of this publication.