Every summer, India sets new heat records. Maharashtra’s Akola recently hit 49.6°C, while Banda in Uttar Pradesh sweltered at 47.6°C. Dr Satchit Balsari, associate professor of emergency medicine at Harvard Medical School and Kartikeya Bhatotia, Research Fellow at the Harvard Mittal South Asia Institute, co-authors of a recent report on extreme heat, spoke to Himanshi Dhawan in an email interview, about its toll on informal workers and the economyIndian summers have always been hot, but what has changed now and how severe could its impact be? What has changed is the nature, frequency, and duration of extreme heat. We are seeing heat that arrives early, persists for longer, and reaches higher temperatures both during the day and at night.The ILO estimates that up to 200 million people in the country could face lethal heat conditions as early as 2030, while rising heat stress is projected to account for tens of millions of lost jobs globally. Millions in the Global South work outdoors, including in India, in both rural and urban settings, and they live in habitats that do not adequately cool down at night. These individuals are now subject to sustained and high heat for longer periods than before, resulting in direct health effects, but also indirectly through disruptions in wages, habitat, and food security. At an administrative scale, prolonged and extreme heat stresses the energy grid as well, further imperiling livelihoods and health.Our understanding of heat threats must move beyond heatwaves and encompass definitions that account for long exposures, nighttime extremes, physiological impact, and importantly, adaptation capacity.What is the impact of heat on human health? Are we prepared? Around the world, deaths from heat make headlines. While this is undoubtedly an important metric, by only measuring deaths we fail to account for the millions of person-hours of suffering and ill health that precede them. The impact of heat on the human body, mediated largely through the cardiovascular system, manifests as heat illness, heat stroke, and ultimately death. Time is of the essence in recognizing and treating these conditions before they turn fatal. Effective management of hyperthermia can be expensive and will need to be contextualised to resource-limited settings in India, where availability of cold water and ice cannot be taken for granted. What we caution against is limiting our imagination to these extremes. Long before, the impact of heat on human health is visible, its effect on existing diseases, like kidney failure, is insidious and damaging. Fatigue and exhaustion result in significant wage losses during the day. At night, shortened and poor-quality sleep for weeks on end precludes recovery. The combined mental health toll is crippling.Individuals working outdoors, or living in poorly ventilated and informal housing, experience greater heat stress than others. Pregnant women, young children, older adults, and individuals on certain medications face disproportionately higher risks.How does heat reinforce income inequality?Informal workers, who make up around 90% of India’s workforce, bear both the highest exposure to heat and the largest share of its costs. Many work outdoors or in poorly ventilated environments and live in housing that does not cool down at night. Informal workers typically lack employer-provided protection, paid sick leave, or enforceable rights to basic safeguards such as shade, water, and rest breaks. There is growing evidence that the poorest suffer significant wage losses during the hottest days, when their own expenses are likely to be highest. They invest in ways to shade their workspaces, cool and hydrate themselves, and pay for heat-related health expenses. The upfront costs of heat adaptation are already being borne by those least able to finance them. Current multilateral funding instruments, of which there are few, that fund heat adaptation efforts do not have a mechanism to reach those most directly impacted.What are the structural issues that need to be addressed to tackle heat?Investment in green spaces that are actually open to the public on the hottest days of the year, along with access to water, sanitation and cooled spaces, merits urgent attention at scale, as several heat action plans have already called for. The urban heat island effect in India is hard to ignore and is devastating to the quality of life of millions of residents.One opportunity to effect change at scale is the Pradhan Mantri Awas Yojana, where until now there has been understandable emphasis on sanitation. Ventilation and passive cooling must now become non-negotiable. The homes of the poor do not cool down adequately at night, and millions return to these spaces throughout the hot months and never fully recover. India has an opportunity to improve conditions for a significant share of the global population most at risk from extreme heat.Heat resilience must be embedded into everyday systems of work, housing, health, and public finance, rather than treated as an episodic crisis.You recommend reframing heat not just as a public health but as a macroeconomic and fiscal risk.Heat is already a macroeconomic variable. There is emerging evidence that heat waves can predict food inflation. We also know that heat reduces labor productivity, increases energy demand, and accelerates wear on infrastructure. These are core drivers of growth, prices, and public expenditure, not externalities that can be easily written off.Extreme heat functions like a recurring negative supply shock. It lowers output, compresses incomes, and increases fiscal pressure at the same time. Govts are already spending significantly on heat through health systems, disaster response, energy subsidies, and water provisioning.Making these costs visible is the first step. Tools like budget tagging can help track heat-related spending and assess whether it is reactive or strategic. Recognizing heat as a fiscal risk also strengthens the case for anticipatory financing, acting before temperatures peak rather than after, because early action is consistently cheaper than post-event relief.Do you think strategies like cool roofs and cool pavements are effective? What more needs to be done?Cool roofs can lower indoor temperatures and reduce surface heat, but typically only by a few degrees. It remains unclear whether that reduction is sufficient to protect health, especially under extreme conditions. Their contribution to reducing the urban heat island effect is meaningful when deployed at scale, but much more limited when coverage is partial.More importantly, focusing on cool roofs alone can create a false sense of progress. Roofs and ceilings are only one part of a building’s thermal environment. Walls, floors, windows, and spatial configuration often play a larger role in determining thermal comfort, as our co-authors Rajan Rawal (CEPT University) and Radhika Khosla (Oxford University) show.They emphasize the need for a shift toward integrated passive design: building orientation, ventilation, materials, shading, and spatial layouts such as courtyards. These strategies address all three modes of heat transfer, conduction, convection, and radiation, rather than focusing on a single surface. Many of these approaches are already embedded in Indian vernacular architecture. The policy aim should be to make them affordable, scalable, and embedded in building codes rather than left to individual choice.As a public health practitioner, I find some of these choices troubling. Those with means do not have to pick between cooling at work, rest at home, and access to water. We can surely do better.How can India build a “cool economy”?A “cool economy”, as we envision it, is one where heat resilience is built into how core systems are designed and operated, not added on as a response to crises. That spans buildings, labor, public health, and infrastructure. It begins with the built environment: scaling passive design, improving housing performance, and reducing dependence on energy-intensive cooling. Cities need shaded public spaces, water access, and infrastructure that reduces exposure. It also requires rethinking work through enforceable protections, adjusted hours, and safer conditions for heat-exposed workers.Health systems need stronger surveillance, trained frontline workers, and infrastructure that can function under sustained heat stress. Once heat is recognized as a recurring economic risk, governments can move toward instruments that support early action, linking forecasts to pre-arranged funding, and integrating heat into social protection and disaster financing systems. A cool economy ultimately shifts from coping with heat to reducing exposure and risk across systems.
