Delhi's story of extreme heat is essentially a story about inequality. In May 2026, the city recorded ‘heatwave conditions’ on the 18th, 19th, 20th, 21st, 24th and 27th, according to the India Meteorological Department (IMD). Warm night conditions occurred over Delhi on the 21st and 25th May, the latter becoming the hottest night in 14 years, the weather monitoring body noted in its monthly report.
This story isn’t about any of those days. Down To Earth (DTE) spoke to outdoor workers in Delhi on May 23, when no temperature records were broken. It had drizzled in the morning and maximum temperatures across the city were in the range of 42-44°C. Although this was above normal, it didn’t meet IMD’s heatwave definition: 4.5-6.4°C departure from normal for two consecutive days recorded by at least two substations.
It was 2pm and delivery worker Jay Yadav, 32, had parked his scooter under the shade of a tree in front of a restaurant at M block market, Greater Kailash II to pick up a food order. When asked how his body reacts to working in the sun, he held out his left hand and pointed to a small bump on his left wrist from a needle-prick. “I was given a saline drip four days ago after I started vomiting and having loose motions at the same time, while also running a fever.” The treatment cost him Rs 2,000 and right after leaving the local clinic, he boarded a bus to his native home in Mainpuri some 290 kilometres from Delhi. “I rested at home for three days but then had to come back to work.” At the end of this short interaction, Yadav broke into silent tears when asked how many hours a day he has to work outdoors. He didn’t have an answer.
In the last few years, particularly since the record-shattering summer of 2024, the public understanding of experiencing heat in cities has evolved from mere monitoring of maximum and minimum temperatures, to factoring in humidity, night-time cooling and impact of urban heat-islands and population density. Even when there is no heatwave warning on a given day, this cocktail of factors may create a potentially unhealthy atmosphere for outdoor work. Moreover, the surface temperatures of roads, vehicles, concrete structures, and other things that surround us when we are outdoors, are significantly higher than the maximum official maximum temperature.
For instance, while IMD was showing a temperature of 41°C at 2pm, Yadav’s scooter's surface was more than 6°C hotter — 47.3°C. This difference over air temperature can be seen in the thermal image below that was developed using an infrared camera, a standard tool to note heat distribution in a space.
An infrared or thermal camera detects infrared radiation emitted by objects and converts it into temperature measurements, explained Aakiz Farooq, climate and energy campaigner at Greenpeace India. Farooq, who was accompanying DTE on this reporting work, studies heat perception among urban communities. “Every object emits thermal energy, and the camera translates differences in emitted energy into colour patterns that represent relative surface temperatures with different colours representing different temperature ranges.”
Surface temperatures strongly influence human comfort and exposure because hotter surfaces increase the amount of heat absorbed and radiated into surrounding spaces, Farooq noted.
Apart from visualising the surface temperatures, we wanted to understand three things: What is the impact of this extreme heat on the bodies of outdoor workers? How do they cool down during the day? Does heat have any financial impact on them?
The symptoms faced by outdoor workers DTE spoke to were headache, feeling feverish or dizzy, and in extreme cases vomiting, loose motion and fainting. The other common experience was that almost all of them had normalised these health symptoms.
“I have headaches and feel dizzy and weak on most days,” said 36-year-old Manish, also a food delivery worker waiting at the same market dotted with restaurants. He said he tries to stay hydrated to cool down but it becomes difficult when he runs out of drinking water while stranded in traffic in the middle of the asphalt road traffic during daytime.
The food aggregator he works for has a couple of resting “hubs” he is aware of, with one of them in Gurgaon — 33km away from where he was working at that point, and none have ACs. The company also didn’t inform him about any water facilities in the city and doesn’t communicate heat alerts, digitally or otherwise, he added.
Employers have been advised to “provide cool drinking water at work place and remind them to drink a cup of water every 20 minutes or
more frequently to stay hydrated”, according to the Public health advisory for extreme heat / heatwave 2026 released by the National Centre for Disease Control (NCDC) under the Union Ministry of Health and Family Welfare. They should also “instal temperature and forecast display at the workplace” and spread awareness among workers about health impacts of heat.
NCDC also advised the general population against “getting out in the sun, especially between 12:00 noon and 03:00 pm” and “strenuous activities when outside in the afternoon”.
At the metro line construction site near Batra Hospital at Vayusenabad, an elderly security guard said he feels lucky that his post is under the shade of the newly constructed metro bridge of the Golden Line and though he works for 12 hours every day, the heat doesn’t bother him, apart from the rashes on his hand. “Sometimes, I feel feverish due to the loo (hot winds) but not frequently,” he added. He said he goes home during the afternoon break and can’t do much else than drink water to stay cool.
On the other side of the road, three workers engaged in building the metro pillar also said the health impacts of the work they do are “negligible”. These three men were 20-40 years of age. They said they take rounds to carry piles of bricks, dig up metalled roads and work with heat-trapping materials such as concrete and metal for 12 hours under the blazing sun. At the elevated platform, where the overhead metro railtrack is being built, there was no cover — from trees or otherwise.
They said they are allowed to rest in shade tents and inside make-shift containers created at the site by the construction company, and are also given 3-hour lunch breaks every day. There were no such shade tents or containers visible in the vicinity of the worksite.
They shared that the company provides medicines to any labourer complaining of physical discomfort from heat. “First-aid kits and ORS are available at the site and ambulances reach here immediately if there’s a health emergency,” said one of the workers who is a surveyor at the project site.
A few feet away, a labourer digging the ground said there is no record of anyone being taken to the hospital in case of sickness due to heat.
But medical experts describe the physiological impact of prolonged extreme heat exposure on human health quite differently. According to Dr Purvi Patel, visiting associate fellow, Sustainable Futures Collaborative, continuous heat exposure generates heat stress to which our body responds by initiating cooling efforts, such as increased blood supply to the skin and increased sweating. These lead to dehydration and increased heart rate as preliminary signs. “This strain on our body is called heat strain,” she said. This is on top of the heat generated due to physical activity and metabolism.
“If the body's heat is not reduced by cooling, shade, rest and water, heat strain can persist and may lead to heat-related illnesses or exacerbate existing diseases,” said Dr Patel, who was formerly a senior consultant for the National Programme on Climate Change and Human Health (NPCCHH) of NCDC.
She explained the multiple ways the human body is impacted by heat exposure. “The effects range from thermal dysregulation, which leads to heatstroke when severely compromised, cardiovascular strain, kidney injury, lung injury, electrolyte imbalance, diarrhea, and spread of intestinal endotoxins, to cognitive and mental health impacts.”
Women, children and elderly are particularly vulnerable to these impacts because of both physiological and social factors, she added.
The hawkers at Lajpat Nagar main market DTE spoke to reported similar symptoms. Balwinder Kaur, a roadside toy-seller in her 30s, said she collapsed at the market 2-3 days ago. When she regained consciousness, she started vomiting and was running a fever. She visited a nearby private clinic where the doctor told her the symptoms were due to heat. She was given an intravenous drip and some medication. The treatment cost her Rs 2,000, she said, a significant share of what she makes in a month.
Next to her, Kusum (50), who sells nylon ropes, said she feels disoriented sitting under the sun all day. There is nothing she can do to cool down other than request for refrigerated drinking water from the shops around. "The water in my bottle becomes too hot to drink."
When DTE visited the Lajpat Nagar main market on May 23, multiple hawkers said there were no government drinking water facilities or public cooling shelters. “We drink water from the tap installed by the market leader,” said Raju, 38, who sells shopping bags. He added that the heat becomes unbearable during 2-3 pm; he splashes his head and face with cool water multiple times to not fall sick.
Their physical suffering is compounded by the impact on their earnings and increased expenses in the summer months. The market was almost empty on a Saturday afternoon — a sharp contrast to the weekend scene during any other season. “Sales have halved since the beginning of May. It feels like this year the footfall reduction is the worst,” said Subhas, 38, who sells kulfi from his cart inside the market. There have been incidents of shoppers fainting during the hottest hours, and most of them were women, he said.
He explained how heat hurts his income beyond low sales. “Usually I buy 50kg of ice every day to keep the kulfi sticks frozen in my box. But during very hot days, I need at least 70 kg. Thus my investment shoots up,” he said. Further, in cooler months, we would even manage to save some ice at the end of the day, but in summer, the entire volume melts away.
All of the four hawkers said they have to cut their work hours by at least three hours during the hottest weeks to minimise heat exposure and also because there are barely any customers.
A 2024 paper found that with every degree rise in daily mean temperature, the earnings of informal outdoor workers fell by 16 per cent. The reduction was 19 per cent for every 1°C increase in wet-bulb temperature, according to the study that factored in the “inability to go to work due to heat in addition to productivity losses on the job”.
These interviews provides a sense of how outdoor workers face income losses even as their health and household expenses due to extreme heat. But a more comprehensive account is found in the personal accounts of labourers as recorded in the garmi khata of “heat registry” that Farooq and his team have circulated among families in Delhi with different income profiles.
In these journals, participants record their heat experiences weekly, which includes how heat affected their health, work, income, sleep, mobility, household expenses, well-being, daily routine, education, among others, Farooq explained.
While almost every person reported experiencing headache, fever, vomiting and low BP, he added that one of the most important findings was how heat affected every aspect of daily life. “Households reported disrupted sleep, increased electricity and water expenses, reduced productivity, loss of income and livelihood (skipping work due to health problems), impact on education (students wrote they were unable to focus during extreme heat days), impact on mental well being and difficulties performing daily routine activities.”
The families were given the diaries since the beginning of May 2026 and have been encouraged to maintain it through July. In one of the diary entries from May 19, 2026, a daily-wage labourer, described how he returned home at 3.30 am from an eight-hour night shift and the electricity went off at 10 am. That was also the hottest day of the month in the city, with the maximum temperature reaching 46.5°C, according to IMD.
"Many participants described making difficult choices between cooling, healthcare, water access and other essential expenditures," said Farooq, who has analysed some of the journal entries. "Women participants, in particular, have written about the additional burden of household responsibilities such as cooking, often in poorly ventilated spaces, which further increased their exposure to heat and compounded physical discomfort and stress."
Babita, a street vendor, from Anand Parbat noted in her diary that the heat affects everyone's mood at home and her family members become irritated more easily. Her children cannot go outside to play and are crammed inside a small room. “Even at night the rooms remain warm. Electricity, fans and coolers become necessities. When there is not enough cooling, the whole household struggles. Food spoils faster, water becomes warm and daily chores take more effort,” she added in her journal entry.
There are multiple dimensions of extreme heat's impacts on the lives of outdoor informal workers engaged in precarious livelihoods and struggling with low income experience extreme heat. While government efforts and advisories to help them cope are visible, the testimonials of these workers
It traps outdoor informal workers in a viscious cycle: While they are most exposed, their capacity to cope with heat stress also reduces with reduced income and poor access to cooling.