India’s heat policy needs to enter the home

India’s heat debate tends to become urgent when temperatures climb and recede when the monsoon arrives. Municipalities publish advisories, hospitals prepare for heat illness, and residents are urged to stay indoors. That last instruction contains an assumption worth examining: that indoors is safer.

For many urban households, a home is a small room beneath a metal sheet or an uninsulated concrete roof. It may have little cross-ventilation, an unreliable electricity connection and several occupants. The roof absorbs heat through the day; the structure can release it long after sunset. Avoiding the street does not necessarily mean escaping dangerous exposure.

The policy question is therefore not simply how India should warn people about heat. It is how cities should make ordinary housing less punishing to inhabit. Cool roofs deserve a larger role in that effort—but only if governments resist turning a useful building intervention into a universal answer.

A warning is not a shelter

India already has a foundation for heat preparedness. Ahmedabad’s heat action plan, introduced in 2013, helped establish an approach combining early warnings, public communication and health-system readiness. Heat action plans have since spread across states and cities. Their existence is progress: heat is increasingly treated as a public-health risk rather than an unavoidable seasonal inconvenience.

Yet a plan can be administratively complete and materially thin. An alert tells a household when danger is approaching. It does not provide a cooler room, compensate a worker for lost earnings or ensure that a fan runs through the night. Advice is least useful when following it requires resources people lack.

Outdoor temperature also gives an incomplete account of household exposure. Roof material, shade, crowding, ventilation and humidity affect indoor conditions. So does the ability to open windows safely. A street-level forecast cannot reveal whether a top-floor room remains hot enough to disrupt sleep throughout the night.

This matters because heat policy is often organised around exceptional days, while harmful indoor exposure can persist across a season. Cities need emergency protocols, but they also need a housing policy for heat. The two should share budgets, responsibilities and evidence rather than operate as separate administrative exercises.

The case for a cooler roof

A cool roof uses a surface that reflects more sunlight and, depending on the material, releases absorbed heat effectively. Options include suitable reflective coatings, tiles and other roofing systems. On an exposed low-rise building, reducing solar heat gain through the roof can lower indoor temperatures and reduce the energy needed for cooling.

The attraction is obvious. Retrofitting an existing roof can be cheaper and quicker than rebuilding a dwelling. It does not require a household to operate an appliance. Where air-conditioning is unaffordable, even a modest improvement in thermal comfort can matter. Where it is already used, a better roof can reduce demand.

Telangana’s Cool Roof Policy 2023–2028 illustrates how the intervention has moved beyond isolated demonstrations into formal policy. Such initiatives offer an opportunity to learn how standards, building permissions and public procurement can support wider adoption. They should also test where the technology delivers enough benefit to justify public spending.

But a roof’s surface temperature is not the same as the temperature experienced by a resident. Indoor gains vary with construction, insulation, ventilation, shading and weather. A dramatic photograph from a thermal camera can establish that a coating reflects sunlight; it cannot, by itself, establish better sleep, lower illness or sustained energy savings.

The strongest case for cool roofs is thus specific, not sweeping. They are especially promising where roof exposure is high and existing thermal protection is poor. They are less likely to transform conditions in lower-storey flats whose heat exposure comes substantially through walls and windows. Climate and season matter too: measures should be assessed locally, including any reduction in useful winter solar warmth.

Who pays, and who benefits?

The economics become harder once a pilot becomes a programme. A coating has an initial cost, a working life and maintenance needs. Dust, weathering, water accumulation and poor application can reduce performance. A cheap procurement contract may become expensive if the surface deteriorates quickly or residents must pay for repeated treatment.

Tenure creates another problem. A landlord may have little incentive to improve a roof when tenants bear the electricity bill and discomfort. A tenant may not invest in a building they could soon leave. In informal settlements, uncertainty over tenure can discourage both private spending and official action, even where exposure is severe.

Public support should therefore follow vulnerability rather than ease of implementation. Municipal buildings are convenient demonstration sites, but the households most in need may live in places with incomplete records and disputed responsibilities. Requiring perfect property documentation would turn an adaptation programme into a filter against its intended beneficiaries.

A practical design would distinguish between building approval and access to basic protection. Assistance for a thermal retrofit need not settle ownership claims or certify every aspect of a structure’s legality. Clear rules are needed, however, so residents do not mistake an improvement grant for a guarantee of tenure.

Funding should cover assessment, safe installation and maintenance, not merely the purchase of material. Contractors should be accountable for specified performance over time. Residents should know what has been installed, how it should be maintained and where to complain. These provisions are less photogenic than a newly whitened roof; they are also what makes the intervention durable.

Cooling is a system, not a product

Roof treatment should sit within a menu of improvements. External shading can prevent sunlight from entering a building. Insulation can slow heat transfer. Appropriate ventilation can help remove accumulated heat when outdoor conditions permit. None is automatically beneficial in every dwelling, and ventilation alone cannot make dangerously hot, humid air safe.

The same caution applies to trees and public cooling spaces. Shade can make streets and public areas more usable, but planting requires space, water and years of maintenance. A cooling centre is of limited use if it is distant, open only during inconvenient hours or inaccessible to people with restricted mobility. Each measure solves part of a problem.

Electricity is the connecting infrastructure. Fans and other cooling appliances are useless during outages. Rising cooling demand, meanwhile, can strain local distribution networks precisely when reliable supply matters most. Heat planning should involve distribution utilities, with attention to vulnerable neighbourhoods, equipment failures and public facilities that require dependable power.

Air-conditioning should neither be presented as the only solution nor dismissed as a moral failure. It can provide essential protection, particularly for people at heightened health risk. But purchasing a unit is not the same as affording its operation. Wider adoption also raises questions about efficiency, peak demand and refrigerants.

The appropriate sequence is to reduce avoidable heat gain, improve affordable cooling and secure reliable electricity, while supporting access to more intensive cooling where necessary. Housing design and appliance policy should reinforce each other. Asking poor households to practise restraint while leaving their homes thermally intolerable is not an equitable energy strategy.

Count safer nights, not painted roofs

A credible urban programme would begin with representative measurements of indoor heat across housing types, seasons and neighbourhoods. These need not become a costly precondition for action. Sample-based monitoring can identify priority building types while immediate support reaches households already known to face severe exposure.

Evaluation should compare treated and untreated dwellings with similar characteristics, record maintenance and account for weather differences. Useful outcomes include indoor heat over the day and night, thermal comfort, electricity use and household costs. Health benefits deserve investigation, but should not be inferred casually from a cooler roof surface.

Municipalities also need a named lead agency, coordination with health and electricity authorities, and funding that survives beyond an emergency allocation. Publishing costs and results would allow cities to learn from one another without pretending that a solution in one climate will perform identically elsewhere.

India does not need to choose between heat warnings and better buildings. It needs to stop treating the former as a substitute for the latter. A roof programme succeeds not when a city reaches a painting target, but when residents can pass a hot afternoon—and recover through the night—with less danger and less expense.