An unprecedented era of heat stress has gripped the Earth. Global temperature records were repeatedly broken between 2024 and 2026, prompting urgent calls for systemic climate action.
“Earth is becoming hotter and more dangerous for everyone, everywhere,” United Nations Secretary-General António Guterres warned the world community, emphasising that while climate change is a universal challenge, its most deadly consequences are concentrated in urban areas.
This urban dimension is explained by the Urban Heat Island (UHI) effect — a well-documented phenomenon by which cities grow measurably warmer than their rural surroundings. The causes are structural: the replacement of natural vegetation with impermeable surfaces such as concrete and asphalt, dense architectural geometries that trap longwave radiation and anthropogenic waste heat generated by vehicles and air-conditioning units. The result is a city that does not merely reflect a warming planet — it actively amplifies it.
Inger Andersen, Executive Director of the UN Environment Programme (UNEP), has underlined that achieving net-zero emissions by mid-century — the minimum required to limit global warming to 1.5°C — demands a fundamental rethinking of cities. Equitable and sustainable urban cooling, she has argued, must be central to that rethinking. In the Global South, however, deeply entrenched demographic realities make equitable cooling especially difficult to achieve.
The anatomy of urban heat in India
India sits at the epicentre of the global heat crisis. In several regions of the subcontinent, temperatures during the pre-monsoon season regularly exceed 50°C. Dr Rajib Chattopadhyay, a senior scientist at the Indian Institute of Tropical Meteorology (IITM), has documented stark microclimatic disparities within Indian cities: dense infrastructure, concrete surfaces and minimal vegetation combine to dramatically intensify heat exposure in already overburdened urban neighbourhoods.
Critically, this is not merely a meteorological problem. India’s demographic profile – so often celebrated as a “dividend” on account of its large working-age population — functions, under conditions of extreme heat, as a vulnerability multiplier of catastrophic proportions.
India’s demographic vulnerability: A matrix of risk
- The informal workforce
More than 80 per cent of India’s labour force is employed in the informal sector: construction workers, street vendors, cycle-rickshaw pullers, agricultural labourers on urban fringes and a rapidly expanding gig-economy workforce of delivery personnel. When temperatures surge, these workers face a brutal choice — forfeit their daily wages and risk hunger or continue working and risk heatstroke and organ failure.
The macroeconomic cost is staggering. According to the Lancet Countdown, heat exposure in India resulted in 247 billion potential labour hours lost in a single year, translating to an estimated $194 billion in foregone income. As Dr Alan Dangour, Director of Climate and Health at Wellcome, observed during the 2026 Mumbai Climate Week: “After a decade of punishing and increasingly deadly heatwaves across India and the wider South Asia region, it is clear that business-as-usual public health approaches are no longer sufficient.”
- High-density informal settlements
Formal housing has failed to keep pace with India’s rapid urbanisation, leaving a significant share of the urban population in slums and informal settlements. These are the ground zero of the UHI effect. In such areas, indoor temperatures frequently exceed outdoor temperatures, denying residents the physiological recovery time that the body needs to survive sustained heat exposure.
- Cooling poverty
While global demand for air conditioning is surging, access remains a privilege. A large majority of India’s urban poor suffers from what researchers term “cooling poverty” — the inability to afford mechanical or technological cooling. Paradoxically, the proliferation of air conditioning among affluent households intensifies the UHI effect in surrounding low-income areas, deepening thermal injustice.
The science-to-policy bridge
The convergence of climatic and demographic vulnerabilities has generated significant momentum in scientific and policy circles. The consensus at recent global summits is unambiguous: addressing urban heat requires dismantling the silos between meteorology, urban planning and public health.
Dr Mrutyunjay Mohapatra, Director General of Meteorology at the India Meteorological Department (IMD), has stressed the need for actionable, hyperlocal intelligence at the intersection of climate and health — particularly to protect communities during acute heat events.
Evaluating India’s policy response
India has been a global pioneer in recognising heat as a disaster. The country led the world in developing city-level Heat Action Plans (HAPs), beginning with the landmark Ahmedabad model, which demonstrated that coordinated early warning systems, hospital preparedness, and public outreach could meaningfully reduce heat-related mortality.
Yet policy analysts note that existing HAPs frequently overlook the demographic complexity of the cities they serve. Urban greening initiatives, despite their popularity, have suffered from spatial inequity: trees tend to be planted in cooler, already affluent neighbourhoods rather than in the dense, informal settlements that most urgently need the cooling and shading benefits of vegetation.
Tamil Nadu’s Urban Greening Policy 2026 offers a more promising template. It directs all Urban Local Bodies (ULBs) to meaningfully expand ecological planning within city development frameworks, supported by robust monitoring systems to enhance climate resilience, biodiversity and public well-being. State Forest Secretary Supriya Sahu has tasked ULBs with achieving a minimum of 15 per cent green cover across municipal limits.
A blueprint for demographic-centric mitigation
India must transition from reactive heat management to proactive, equity-driven heat mitigation. A comprehensive policy framework must rest on four pillars.
Occupational heat governance: Extreme heat must be formally recognised as a workplace hazard. The state must scale up and subsidise innovative financial instruments such as the parametric heatwave insurance developed by the Self-Employed Women’s Association (SEWA), which provides cash transfers to informal women workers when heat crosses dangerous thresholds.
Passive cooling mandates: Urban building codes must require passive cooling in all new construction. Interventions as simple as cool roofs – reflective white paint applied to rooftop surfaces – can reduce indoor temperatures by 2°C to 5°C at minimal cost.
Equitable Green and Blue Infrastructure: Nature-based solutions must be democratised. Urban greening programmes should deploy vulnerability mapping to prioritise the planting of native, shade-providing trees in low-income neighbourhoods, pedestrian corridors and public transit routes.
Hyperlocal, Data-Driven Forecasting: India must harness artificial intelligence and high-resolution satellite imagery to forecast heat hazards at the ward and neighbourhood level. Municipal corporations can then pre-position resources — cooling centres, emergency water supply, early warning systems and medical provisions — before extreme events occur.
The scorching face of urban injustice
Extreme heat is not a great equaliser — it is a cruel amplifier of pre-existing socioeconomic fault lines. Indian cities can remain engines of economic opportunity rather than arenas of thermal injustice only if urban planning becomes profoundly egalitarian, science-driven and transformative. The stakes are nothing less than the health, productivity and dignity of hundreds of millions of people.
UPSC Mains practice questions
Q1. (GS Paper III – Environment and Disaster Management)
“Heat Action Plans in India have prioritised early warning over equity.” Critically examine the limitations of India’s existing urban heat governance framework and suggest a demographically sensitive policy architecture to address thermal vulnerability in cities.
Q2. (GS Paper II – Social Justice and Governance)
The concept of ‘cooling poverty’ exposes the intersection of climate change, urban informality and social inequality. Discuss how the urban poor in India are disproportionately exposed to extreme heat and evaluate the role of the state in ensuring equitable access to cooling as a public good.