Model Answer

Urban heat risk emerges from the interaction of rising temperatures, the Urban Heat Island effect and unequal adaptive capacity. Delhi’s recent “heat diaries”, recording surface temperatures above 54°C in Sunder Nagri, demonstrate how extreme heat disproportionately affects the urban poor.

Why Indian cities are becoming hotter

1. Built-up surfaces absorb and re-radiate heat. e.g: Concrete and asphalt intensify Urban Heat Island effect.
2. Loss of vegetation reduces natural cooling through evapotranspiration. e.g: Declining tree cover in dense neighbourhoods.
3. Dense construction restricts ventilation and traps heat.
4. Anthropogenic heat adds to ambient temperatures. e.g: Vehicles and air-conditioners.
5. Climate change increases the frequency and intensity of extreme heat events.

Why extreme heat is a climate-justice challenge

1. Poor housing amplifies indoor heat exposure. e.g: Tin-sheet and poorly ventilated dwellings in informal settlements.
2. Outdoor workers cannot easily avoid peak temperatures. e.g: Street vendors and construction workers.
3. Limited access to affordable cooling increases vulnerability. e.g: Electricity costs constrain cooler use.
4. Heat reduces incomes and productivity. e.g: Lower customer footfall and faster food spoilage among vendors.
5. Health impacts are socially unequal. e.g: Heat diaries report dehydration, headaches, fatigue and sleeplessness.

Building heat-resilient and inclusive cities

1. Heat Action Plans must map neighbourhood-level vulnerability. e.g: NDMA guidelines recommend vulnerability assessments.
2. Passive cooling can protect low-income households. e.g: Cool roofs can reduce indoor temperatures by 2–5°C.
3. Green-blue infrastructure can reduce urban heat. e.g: Trees, shaded streets and water bodies.
4. Cooling centres and drinking-water points can protect vulnerable populations.
5. Heat resilience must enter urban planning and building regulations. e.g: ECBC-based heat-resilient construction.

Way Forward

1. Make ward-level heat-risk mapping central to Heat Action Plans.
2. Scale cool roofs and climate-resilient housing in informal settlements.
3. Provide occupational heat standards, cooling shelters and social protection for outdoor workers.

Extreme heat exposes inequalities embedded in urban form and access to resources. Climate-resilient cities must therefore combine heat mitigation with housing, livelihood and social protection for vulnerable communities.