For workers in Delhi’s deadly heat, cooling zones can only offer a temporary respite

Near Dhansa Bus Stand Metro Station in South West Delhi, a white marquee tent designated as a “cooling zone” was set up by the state government this summer. The facility is part of Delhi’s heatwave response, under which 14 cooling zones have been established in eight districts. In addition, 13 “mobile heat relief units” that distribute water, oral rehydration solution and other heat-relief supplies have been set up across the city.

For those able to reach them, these facilities offer something simple but critical: a reduction in the body’s heat burden. High temperatures, humidity and physical exertion can together dangerously overwhelm the body’s ability to cool itself. This could cause fatigue, dizziness and dehydration, and in severe cases, heat stroke.

Measurements in the Dhansa cooling zone around 2.30 pm on June 1 showed a clear contrast: outside, the air temperature was 38.9°C; inside it was 33.3°C. Globe temperature – a measure of radiant heat from surrounding surfaces – fell from 43.8°C outside to 34.3°C within.

The Wet Bulb Globe Temperature, a measure of environmental heat stress that combines the effects of temperature, humidity, radiant heat and air movement on the human body, was 33.5°C outside and 29°C inside.

The World Health Organization and World Meteorological Organization classify a Wet Bulb Globe Temperature of 32°C as high occupational heat stress. This means that the Wet Bulb Globe Temperature reading of 33.5°C recorded outside the tent in Delhi indicated extreme heat-stress conditions for sustained outdoor work.

However, protection depends not only on whether such facilities work, but also on who can access them and for how long. A short distance from the cooling tent, a juice seller continued serving customers despite the heat.

He occasionally used the facility to refill water, but his earnings depended on staying by his cart outside. “The tent is nearby, but I cannot stay there,” he said. “If I leave the stall, I lose customers.”

His predicament is not unusual. Across Delhi, extreme heat is experienced unevenly. While some residents can retreat into air-conditioned homes, offices or metro stations, many others remain exposed because their livelihoods require it.

Official advisories recommend avoiding outdoor exposure between noon and 4 pm, staying hydrated and reducing strenuous activity. From a public-health perspective, the advice is sensible.

But it assumes that people can withdraw from heat when necessary – an option unavailable to those whose livelihoods depend on being outside throughout the day, including the afternoon hours. For them, heat is a part of their working conditions.

Across Delhi, that reality was visible in a range of workplaces we visited in May and June: construction sites, roadside markets, waste collection points and transport corridors. During the hottest part of the day, workers continued to labour even as temperatures exceeded 40°C and reached 45°C at some locations.

“If we stop, who will pay us for the day?” one construction worker asked.

For street vendors, even a short break could mean missed customers and lost sales. Heat imposed a double burden: it reduced physical capacity while also threatening income. About 70% of the outdoor workers we surveyed reported heat-related health concerns, including exhaustion, headaches, dizziness, dehydration and disrupted sleep.

Leaving work is not an option

In Kusumpur Pahari, an informal settlement near Vasant Vihar in New Delhi, a sanitation worker was clearing waste from an open dump site at 1.30 pm. Field measurements recorded an air temperature of 43°C and a Wet Bulb Globe Temperature of 36°C – conditions that pose a serious risk of heat stroke for anyone doing sustained physical labour.

There was no rest area, drinking-water facility or visible heat-protection measures. “The heat is difficult, but the work cannot wait,” the man said.

Some workers improvised their own protection. On the campus of Jawaharlal Nehru University, an auto-rickshaw driver had placed a mattress on the top of his vehicle to reduce the heat in his vehicle.

“The roof gets very hot under the sun,” he said. “The gadda helps reduce some of that heat, so it feels a bit better inside for both me and the passengers.” In the absence of formal protection, workers try to make their own workplaces bearable.

Extreme thermal exposure was evident in more formal workplaces as well. At a shopping complex near Chandni Chowk in Old Delhi, surrounding surfaces recorded a temperature of around 65.1°C during working hours. Security and sanitation staff remained there through their shifts, exposed not only to high air temperatures but also to intense radiant heat from the surrounding paved and built surfaces.

The most striking observation was at the main gate post of Jawaharlal Nehru University, where thermal imaging recorded the corrugated metal roof of a security post at 84.64°C – the highest surface temperature documented during the survey.

A guard stood beneath the structure, while another nearby held an umbrella for shade. The roof intended to provide shelter had become a source of exposure, radiating heat onto the workers below.

Together, these sites show how dangerous heat is built into the everyday spaces of urban work. Workers remained on duty while the surfaces around them absorbed and radiated dangerous levels of heat. Even where some form of shelter existed, it was inadequate for Delhi’s extreme summer conditions.

Reducing heat exposure

This points to a larger problem. Delhi’s heat response is equipped to offer relief after exposure rather than reduce exposure where it is produced.

In May, announcing the expansion of Delhi’s heat-relief programme, Chief Minister Rekha Gupta said, “In a metropolitan city like Delhi, where even a glass of cold water is often not easily available to people, these initiatives launched by the government are providing real relief.”

These initiatives are important, even life-saving. But in a city of more than 23 million inhabitants, 14 cooling zones and 13 mobile heat relief units cannot by themselves address the scale of urban heat exposure.

For workers who cannot leave their worksites, a cooling tent or mobile supply of water and ORS can only offer temporary relief that is not the same as protection at the worksite itself.

Reducing heat exposure requires ordinary but essential changes: shade along pedestrian corridors, covered vending areas, worker rest stations, safe drinking water, reflective roofing, better ventilation, flexible work hours and scheduled rest breaks during peak heat.

These measures remain largely outside the scope of emergency heat responses. The result is cooling measures that respond to crises rather than prevent the conditions that create them. Heat is still being governed as a seasonal emergency rather than a intrinsic part of urban life in a changing climate, especially during summer months.

The challenge now is for Delhi to reduce exposure where it is produced: in the streets, workplaces and infrastructure that shape everyday urban life. Until then cooling zones, like the one at the Dhansa Bus Stand Metro Station, can only offer a respite as life goes on outside in the extreme heat.

All photographs were taken during the field study carried out by the authors.

Rakhohori Bag is a research scholar at the Centre for the Study of Regional Development, Jawaharlal Nehru University. His research focuses on climate justice, environmental inequality and urban governance in cities of the Global South.

Sneha Saha is a research scholar at the Centre for the Study of Regional Development, Jawaharlal Nehru University. Her research focuses on gendered vulnerability and adaptation to climate change in urban India.