On April 30, 2024, a day before International Workers Day, Vijesh Kaniyeri, a 41-year-old building painter from Kozhikode district in the Indian state of Kerala, fainted while washing up for lunch. “His body temperature had become too high,” Pushpa T, his sister-in-law, said. “He was put on a ventilator at the hospital but never regained consciousness.” Kaniyeri died two days later.
With temperatures hovering at over 40 degrees Celsius in parts of the state at the time, Kerala had issued an official heatwave alert on 29 April, a day before Kaniyeri collapsed. It issued an orange alert, its second most severe alert category, for areas of Palakkad district; and a yellow alert, indicating heat tolerable for the general population but suggesting caution for the vulnerable, for Alappuzha, Thrissur and Kozhikode districts. The administration urged people in these areas to avoid outdoor work between 11 am and 3 pm. It also stressed the need for vigilance against heat stroke and listed precautions, such as ample hydration, to mitigate health risks.
“Vijesh had not worked for a week because of the heat,” said Pushpa. He had followed advisories and heat warnings in the media. But the advisories did not come with provisions to cover wages lost. “He had no money left,” she said, explaining what prompted him to go to work on the fatal day.
Muhammad Haneefa, a 62-year-old mason from Padinjattumuri in Malappuram district, died in the early hours of 2 May – the same day that Kaniyeri died. He had fainted the previous day at work. “He had no other health issues,” Moidukutty, Haneefa’s brother, said. “Sun stroke is what the doctors said led to his death.” Malappuram was not on the list of districts for which heatwave alerts had been issued.
Ultimately, neither Kaniyeri nor Haneefa’s deaths were classified as being heat-related, because neither of their post-mortems listed heat as the cause of death. India has a massive problem of undercounting heat-related deaths. Without an understanding of the growing incidence of extreme-heat fatalities, the country lags behind on impactful heat-action strategies, especially for its large population of outdoor workers. Ineffective heat advisories without localised and actionable features do little to nothing to address the problem.
The Indian Meteorological Department (IMD) defines a heatwave as a period of unusually high temperatures as compared to what is normally expected over a region. Excessive heat exposure affects the human body’s ability to maintain optimum internal temperatures. A 2024 research report by the World Economic Forum predicts the loss of 1.6 million lives to heatwaves globally by 2050. The people most at risk are outdoor workers, the urban poor, pregnant women, people with existing medical conditions, the elderly and the young, as well as those who live in substandard housing without proper ventilation or other cooling mechanisms.
Heat causes blood vessels to dilate and blood pressure to drop, thereby putting strain on the heart. Kidney function can be affected as sweating causes loss of fluids and salts, which leads to electrolyte imbalances. This increases the risk of heat stroke, which can then lead to organ failure. Heatwaves especially increase health risks for those with chronic conditions such as high blood pressure, heart disease or diabetes.
Globally, 2024 was the warmest year on record, with average near-surface temperatures at about 1.5 degrees Celsius above the pre-industrial baseline level. It was also the hottest year in India since record-keeping began in 1901. Many parts of India hit their all-time highest maximum temperatures over the past year.
Source: National Data Centre, IMD Pune
Kozhikode, where Kaniyeri lived, saw two of its highest daily maximum temperatures ever. In Kozhikode, 2024 broke records for the highest daily minimum temperatures, with nine of the top ten highest minimum temperature days ever witnessed. Higher night-time temperatures affect heat dissipation and exacerbate the effects of heat on the human body.
In the past, heatwaves have not been a common phenomenon in Kerala, which lies at the southern tip of India. The closest the state had come to having one before 2024 was in 2016, when Palakkad district recorded a temperature of 41.9 degrees Celsius – the highest since 1901. But summer temperatures have become increasingly severe in recent years. Palakkad recorded six of its ten highest maximum temperature days in 2024.
Studies have shown that human-induced climate change has made extreme heat events more likely or more severe worldwide. The 2022 heatwave that affected large parts of India and Pakistan was made at least 30 times more likely by human-induced climate change. Going forward, scientists say, anthropogenic climate change will make summers hotter, with more frequent and more intense heatwave conditions.
The IMD has a network of automatic weather stations (AWS) and surface manual observatories to track heat. An AWS uses sensors and automated data loggers to record weather data, while manual stations rely on human observers to record readings. Scientists generally regard manual observatories as giving more accurate readings. An AWS is often exposed to environmental factors like direct sunlight, which results in faulty readings. In 2024, an AWS in Delhi recorded a temperature of 52.9 degrees Celsius – the highest ever reading in India – due to a sensor error. “The temperature readings from automatic weather stations are unreliable,” a senior scientist at an IMD station, who did not want to be named, said. The IMD relies on data from manual observatories to issue alerts.
Automatic weather stations also lack sufficient historical data to detect long-term temperature deviations, necessitating reliance on manual observatories instead. IMD documents show a network of 547 surface manual observatories across more than 750 districts in India. Regular data is available from 438 of these. In Kerala, not all 14 districts have manual weather monitoring stations. Kasaragod, at the northern tip of the state, Pathanamthitta near south-central Kerala, and the two hill districts of Idukki and Wayanad, all have no manual observatories. When I spoke to a Kerala State Disaster Management Authority (KSDMA) official this February, he told me that the manual station at Alappuzha was not functional at the time.
The situation is worse across much of the rest of India. Uttar Pradesh – India’s most populous state, and one of the states most severely affected by heatwaves – has 33 manual stations for its 75 districts. Rajasthan, which regularly records the highest temperatures in India, has 22 manual surface stations for its 50 districts.
State disaster-management authorities issue district-level alerts based on input from the IMD, relying on climate models along with real-time data from surface observatories. According to experts, the resulting alerts are inadequate. “We haven’t developed an accurate system to alert heatwaves,” a senior climate scientist and academic said on condition of anonymity. “Warnings and alerts must be specific. What we have are general awareness announcements.”
Abhilash S, the director of the atmospheric radar research centre at the Cochin University of Science and Technology, said that without specific localised inputs to inform the alerts, efforts to mitigate the effects of a heatwave are reduced to government bodies and social organisations providing drinking water on roadsides. “By issuing generalised warnings, the advisories lose urgency in the public eye,” he said. Focussed measures – such as cooling centres for the vulnerable, or targeted social support and localised curfews to restrict movement and work in the most severely affected areas – can help people much more.
Another problem is the lack of clear definitions for heatwaves. The IMD has three criteria for declaring a heatwave – one based on departure from normal temperatures, the second based on actual maximum temperatures and a third applicable only for coastal regions. When temperatures touch or exceed 40 degrees Celsius in the plains or 30 degrees Celsius in the hills, a heatwave condition is reached if the maximum temperature departure from normal is 4.5 degrees Celsius or more. Additionally, a heatwave condition is reached when the maximum temperature crosses 45 degrees Celsius. For coastal areas, a heatwave can be declared when the maximum temperature touches 37 degrees Celsius and there is a 4.5-degree Celsius departure from normal maximum temperatures.
But relying on temperatures alone discounts fluctuations in humidity. “In places with humidity, the feel-like temperature is always higher than the real temperature,” Abhilash said. “This causes heat stress. This is different from central India, where even 45 degrees won’t cause as much heat stress as a 38 degree here,” in Kochi. In high humidity, sweat does not evaporate and the body’s ability to cool itself is hampered.
A better way to account for heat stress is to use a heat index, which conveys what it feels like to be exposed to a particular combination of air temperature and other meteorological factors, primarily humidity. The IMD and some states, such as Karnataka, recognise the importance of a heat index that factors in relative humidity when predicting a heatwave. In 2023, the IMD launched a heat index on an experimental basis; in the summer of 2024, it issued heat index-based alerts for Delhi. But the IMD still does not use a heat index countrywide.
“A heat index of 50 is considered a very high temperature. Kerala hits 50 regularly,” Fahad Marzook, a hazard analyst with the atmospheric science section at the KSDMA, said. In late April 2024, Kerala met the IMD’s conditions for a heatwave – a rare occurrence for the state. Parts of the state recorded maximum temperatures of 40 degrees Celsius and a temperature departure from normal of 4.5 degrees Celsius. On 29 April, when the heatwave alert was issued, Kozhikode recorded a maximum temperature of 38 degrees Celsius and a highest minimum temperature of 29.2 degrees Celsius.
But the state had been in the grip of severe heat and humidity for many days before the official alert. Kozhikode had already recorded a maximum temperature of 38 degrees Celsius on 12 April – a record for that station. It had all-time-high minimum temperatures for five nights between 11 April and 17 April.
Kozhikode in Kerala has seen its average surface temperature increase by 7 °C in the last 30 years because of urban heat island effect as per studies. Seen here is the historical satellite view of Chakkumkadavu in Kozhikode where Vijesh lived. Scientists blame land use pattern changes and climate change for the intensifying summers. Graphic: Jeff Joseph using Google Earth
Many heatwave experts point out discrepancies in heatwave data because observatories are often located away from urban centres and end up recording lower temperatures. “The IMD Palam observatory in New Delhi is further away from the city centre which makes its readings less accurate for predicting heatwave conditions within the city,” Dileep Mavalankar, the former director of the Indian Institute of Public Health, Gandhinagar, said. Mavalankar was instrumental in designing India’s first heat-action plan, implemented in the city of Ahmedabad in 2013. This provided immediate and long-term strategies to reduce the impacts of extreme heat on the city’s most vulnerable populations. It also provided a template for plans now being implemented in 23 states prone to heatwave conditions.
“The issue of urban heat islands too isn’t factored in by the IMD when declaring heatwaves,” Abhilash said. Heat islands can raise temperatures in urban areas and city centres by between two to four degrees Celsius compared to surrounding areas. One study has shown that, over the years, Kozhikode has seen a substantial rise in average land surface temperature, from 23 degrees Celsius in 1993 to 30 degrees Celsius in 2022, due to the effects of urban development. (The image above shows the expansion of Kozhikode’s urban sprawl between January 2010 and January 2025.)
Even some of the IMD’s own top scientists and administrators admitted, on condition of anonymity, that India’s heatwave alert system needed to be updated.
On October 6, 2024, hundreds of thousands thronged an Indian Air Force air show at Marina Beach in the city of Chennai, in Tamil Nadu. According to news reports at the time, five attendees died from heat stroke and more than a hundred people were admitted to hospitals seeking medical treatment for heat-related issues after the event. Ma Subramanian, the health minister of the Tamil Nadu state government, confirmed the deaths, saying they were due to “high temperatures”. However, the monthly data on confirmed heat-stroke deaths for 2024 from the National Centre for Disease Control (NCDC) lists just two confirmed heat-stroke deaths and 116 suspected heat-stroke cases from Tamil Nadu, with no deaths recorded after July. This is because the data on heat-related illnesses and deaths in India is collected only through the months of March, April, May, June and July.
As per information from the NCDC, the country had 189 confirmed cases of heat-stroke deaths and 19,388 cases of suspected heat stroke in 2023. But in 2024, despite a higher number of suspected cases of heat stroke, totalling 48,001, as well as a more intense summer, the data shows just 159 heat-related deaths. No heat-related deaths were recorded in 2021.
Independent studies show much higher death tolls from extreme heat in India. Mavalankar was part of a study that looked into excess mortality during a heatwave in Ahmedabad in 2010. It showed a high correlation between daily maximum temperatures and excess mortality. The total number of deaths during May that year was 4462 – a 43 percent increase from other years – and 1344 were associated with heat.
A recent analysis of district level excess mortality from a University of California Berkeley researcher showed that a single heatwave day causes 3400 excess deaths in India. A five-day heatwave causes about 30,000 excess deaths. If there are five heatwaves of five days each during summer, it can cause 150,000 excess deaths, the researchers say, calling this massive number a conservative estimate.
In a radio address to the country in February 2018, India’s prime minister, Narendra Modi, made the claim that thousands of people would lose their lives every year due to heatwaves until a few years ago. “The NDMA organised workshops on heatwave management as part of a campaign to raise awareness among people,” Modi said. “Mass participation led to good results reducing deaths to 220 in 2017.”
The number of heat-related deaths in the official tally did drop significantly and one of the factors for low numbers in recent years may be a change in the way such deaths are being counted. In a report on reducing heat-related mortality, the National Disaster Management Authority claimed that the introduction of committees to verify deaths from heat waves helped bring the numbers down. “Over-reporting of heat-wave deaths—done for the purpose of seeking monetary compensation for the families of the dead—has been nearly brought to an end,” the report said. But officials on the ground note that the criteria for a heat-related death has become only death by heatstroke. “The central officials tell us to not even follow up on other heat-related illnesses or issues such as sunburns,” an official from Kerala’s health department said. This discounts a large number of deaths that can be triggered by extreme heat.
India has a dedicated Integrated Health Information Platform that collates data on heat-related illnesses and deaths, among other things. This is managed under the health ministry’s National Programme on Climate Change and Human Health (NPCCHH). The data for 2021 showed that 17 out of 24 Indian states and union territories had failed to report heat-related deaths, while the remaining seven reported none. For 2022, nine failed to report heat-related deaths while 10 reported zero deaths.
Often, different government sources have different numbers. In August 2024, Anupriya Patel, a union minister of state for health and family welfare, said that there had been 48,385 suspected cases of heat stroke and 185 confirmed heat-stroke deaths in India up until 28 July that year. As per data collected under the National Heat-Related Illness and Death Surveillance programme, there were 48,156 suspected heat-stroke cases in 2024, with 269 suspected heat-stroke deaths and 161 confirmed heat-stroke deaths. As previously noted, the NCDC cited slightly lower figures for suspected cases and confirmed deaths. In his February 2018 address, Modi cited 220 deaths for 2017, which was lower than the NCDC toll of 384. But experts see all these figures as undercounting the true toll by many orders of magnitude.
One likely reason for undercounting heat-related deaths is that there are no pathological tests to confirm such deaths. Excess heat causes organ failure, which is very often what is documented as the cause of death in heat-related cases. A heat-stroke is indicated by the rise of core body temperature above 40 degrees Celsius and dysfunction of the central nervous system. “Survival chances of heat-stroke cases are low,” Abdul Nissar, the district nodal officer for climate change in Malappuram, said. “If there is no intervention to cool the body by pouring cold water over it immediately, the chance of death is very high. Most won’t survive.”
Heat stroke can be of two types – exertional, when caused by strenuous activity; and classic, when it results from passive exposure to extreme heat. Exertional heat stroke most often occurs in people employed in physical labour outdoors, usually under direct exposure to the sun, like in the cases of Kaniyeri and Haneefa. Classic heat stroke is often seen in vulnerable populations such as those with comorbidities, and can often occur even while people are indoors. “Ninety percent of heat-related deaths are in people with comorbidities,” Mavalankar said. People with obesity, cardiovascular disease, respiratory disease and diabetes are more at risk from heat-related illness. Some medicines for cardiac conditions and diuretics for managing hypertension have been found to increase the risk of heat stroke.
This February, Sekhar Lukose Kuriakose, the member secretary of the KSDMA and the head of Kerala’s emergency operations centre, told me that no heat-related deaths had been recorded in the state for 2024. “Confirmation has to come from the health department that this is a heatwave-related death, through a medico-legal process,” he said.
Post-mortems form the basis for the classification of heat-stroke deaths. “The post-mortem report didn’t confirm the death as caused by heat stroke,” M Bijulal, a councillor with the Kozhikode Corporation, said about Kaniyeri’s death. Haneefa’s post-mortem report also did not say anything conclusive about the effect of heat.
“In suspected cases, a laboratory confirmation is sought,” R Renuka, the district medical officer for Malappuram, said. After a suspected heat-related death is reported, an investigation is conducted by a team that includes an epidemiologist and a specialist, who look at the autopsy report. The cause of death is eventually certified by the district surveillance officer and reported to the state. Information from the Kerala state health department showed that of five suspected heat-stroke deaths in 2024, only two cases were confirmed by post-mortem – neither of them involving Kaniyeri or Haneefa.
When people with comorbidities die during an extreme heat event, often their underlying conditions are documented as the causes of death, Nissar explained. This stand in the way of their cases being recognised as heat-stroke deaths. “Forensic surgeons are not sufficiently exposed to heat-stroke deaths and don’t factor them in sufficiently,” he said. “That is why such deaths get classified as heart attacks or organ failure depending on underlying conditions even if it was caused by heat.”
Kerala has one of the most advanced public health systems within India. But while Kerala’s health department shows two confirmed cases of heat-stroke deaths in 2024, its disaster-management authority claims that the state had none. Media reports during the summer of 2024 listed at least five such deaths, including Kaniyeri and Haneefa. NCDC data cites 14 altogether, including suspected heat-stroke cases and one confirmed heat-stroke death.
Mavalankar stated that, to get a truer picture of the number of people at risk and dying due to extreme heat, India needs to go beyond absolute numbers of heat stroke deaths and look at excess mortality. In a study published last year, researchers evaluated global, regional and national mortality associated with heatwaves for the period between 1990 and 2019. They found more than 150,000 excess deaths occurred globally every summer. with close to half of these occurring in Asia and a fifth – roughly 30,000 deaths – just in India. A multi-city study on the impact of heatwaves that occurred between 2008 and 2019, looking at all-cause mortality in 3.6 million deaths in India, showed that a two-day heatwave was associated with a 14.7 percent increase in daily mortality.
Despite reported undercounting, the United States, with its population of 334 million people, counted 2300 heat-related deaths in 2023. In the United Kingdom, as per the government’s heat mortality monitoring report, there were an estimated 2295 deaths associated with heat in the summer of 2023. The number of people in the United Kingdom aged above 65 – a group in which heat-associated deaths are especially prevalent – was 12.7 million. As of 2011, when India released its last census, the country had 104 million people aged 60 years and above. Even accounting for deaths in the intervening period, India currently has a population above the age of 70 that is likely greater than the entire population of the United Kingdom. Yet the recorded numbers of heat-related deaths here, where extreme heat is far more prevalent, remain far below those in the United Kingdom.
These studies and comparisons call into question the Indian government’s official numbers on heat-related deaths and the methods used to count them, especially as summer temperatures continue to break records every year and heatwaves become increasingly common and intense across the country. Unlike the United Kingdom, which calculates heat-related deaths based on excess mortality, India only considers confirmed heat-stroke deaths in its tally of heat-related mortality. “We are far off from reporting most of the deaths and illnesses,” Mavalankar said.
Kerala’s Heat Action Plan provides for compensation of INR 4 lakh – roughly USD 4700 – to families of the victims of heat-related events. Although Kaniyeri’s death was never recorded as being heat-related, his parents, 94-year-old Kumaran K and 73-year-old Vasanthi, who were financially dependent on their son, applied for relief from the state. A year later, they have received no response.
While many states have adopted centrally-mandated heat action plans that sometimes include compensation, a lack of funds typically makes such provisions meaningless. India has 12 types of notifiable disaster at the national level – cyclones, droughts, earthquakes, fires, floods, tsunamis, hailstorms, landslides, avalanches, cloudbursts, pest attacks, frosts and cold waves. Victims of these disasters are eligible for relief assistance from national and state-level disaster relief funds (SDRF). “Heatwaves are not a nationally notified disaster in India,” said Marzook of the KSDMA. As a result, “states can spend only a maximum of 10 percent of the SDRF for heatwave mitigation efforts.”
State governments can use up to 10 percent of their annual disaster-relief funds to provide immediate relief to the victims of state-specific natural disasters not recognised as nationally notified disasters. Kerala notified heatwaves, as well as outbreaks of sun stroke and sunburn, as state-specific disasters in 2019. In 2024, the state of Tamil Nadu declared heatwaves to be a category of state-specific disaster. Rajasthan, Chhattisgarh, Odisha, Maharashtra, Karnataka and Andhra Pradesh have done so too.
In 2024, Kerala had INR 783 crore, or roughly USD 90 million, for disaster relief after combining new allocations and leftover budget allocations from the previous year. Massive landslides in Wayanad district last year drew the government’s attention and its relief funds. With landslides and cyclones and the property damage they cause, politicians are often eager to be seen as providing relief to the victims. “When there is visible damage, political interests come in,” Mavalankar said. “The issue with heatwaves is that there is no property damage, so it isn’t visible.” This acts against their victims.
As per information obtained through a Right to Information request, Kerala’s health department allocated a measly INR 50,000 to each of the state’s 14 districts in 2024 to deal specifically with heat-related illnesses. Under the NPCCHH, the central government allocated INR 100 crore to all Indian states and union territories together. This funding was to be split between mitigation efforts related to multiple climate-related issues, including extreme heat, air pollution, extreme weather events and vector-borne diseases, as well as the adoption of climate-resilience measures in health care facilities.
By 2030, 500 million people around the world are expected to be exposed to extreme heat for at least a month every year. The largest proportion of the exposed is expected to be in India and Pakistan, followed by Bangladesh. Poor and deprived, the most vulnerable people in these countries cannot protect themselves from this threat. Ineffective advisories, undercounting of heat-related illnesses and deaths, and the absence of meaningful relief and support are common problems across Southasia.
In 2024, the Pakistan Meteorological Department forecast a heatwave across most of the country and primarily in the Sindh province between 20 June and 24 June. Much like in India, the preparations to mitigate heat-related illnesses and deaths were largely limited to setting up roadside camps to provide drinking water. Advisories for limiting movement proved inadequate. Between 20 to 26 June 2024, 568 deaths were reported from Karachi alone. The actual number was thought to be much higher. “Around 1100 to 1200 [heat-related] deaths were recorded,” Saqib Baqar, a Karachi-based journalist who covered the heatwave, said. “Most of the deaths were in the thickly populated areas in old areas of Karachi. The old were said to be most at risk. But even young people without any previous health risks died from heart failure.”
“Even when alerts predict high temperatures and heatwaves, workers have no other option but to work,” Sheema Siddiqui, a Karachi-based journalist, said. “People who were working in mandis [markets] and factory workers in Karachi were severely affected. They cannot afford mitigation measures such as coolers,” and the government did not provide support for such mitigation measures.
Pakistan is yet to announce specific relief provisions for heatwave deaths. Its heatwave action plan for 2024, released by its national disaster-management authority, does not mention relief and compensation for heat-related illnesses or deaths.
Around April 2024, many parts of Bangladesh experienced heatwaves for 30 consecutive days. This was the longest heatwave period the country had seen since 1948. “Advisories are ad-hoc and not pre-emptive,” M Zakir Hossain Khan, the chief executive officer of the Dhaka-based think-tank Change Initiative, said.
“Factory owners were not made aware of the upcoming heatwaves,” Khan said. “It is important for managing labour productivity. But they continue to conduct business as usual.” The textile and garment industry in Bangladesh, which employs around 5 million and generates more than 80 percent of the country’s export revenues, is based primarily in urban centres such as Dhaka, a city which sees amplified effects of heatwaves due to the urban-island effect.
“Industrial workers are more vulnerable in Bangladesh,” Ahmad Kamruzzaman Majumder, the dean at the school of science at Stamford University Bangladesh, said. “Many industries do not have the means to provide air conditioning. When faced with power shortages, industries compensate by taking out air conditioning.”
“During extreme heat, access to electricity is very important. But what we see is that severe load-shedding happens during heatwaves,” Khan said, referring to power cuts. On 28 April 2024, during peak summer, Bangladesh saw load-shedding cross 1860 megawatts, its highest power shortage in a decade. “At times, even if factories have air conditioning, workers must return to homes without any cooling measures,” he said. Health experts also say that long exposure to air conditioners can decrease the human body’s adaptability to heat,creating increased risk of heat-related illnesses. Information on casualties in Bangladesh’s textile mills is not coming out, Kamruzzaman said. “They are treated as industrial accidents and kept secret.”
A 2024 International Labour Organisation report showed that at least 2.4 billion workers are exposed to excessive heat at work every year. More than 80 percent of India’s labour force works in the informal sector. A study on informal-sector workers in the slums of Delhi found that net earnings fell by 40 percent and earnings declined by 19 percent on heatwave days for every one-degree Celsius increase in wet-bulb temperatures. Under intense heat, daily-wage workers risk death to make a living.
Nepal too has increasingly been seeing the impacts of heatwaves. Last June, heatwaves in the country’s Terai region saw schools being shut for three days. “The rising temperatures in the mid-hills and mid-mountains of Nepal are alarming,” Anil Pokhrel, the former chief executive officer of Nepal’s disaster risk reduction management authority, said. “Even if the temperatures are only 35 degrees, the people in these areas and their livelihoods are not adapted to such temperatures.”
Unlike in India, Pakistan and Bangladesh, where heatwaves are a somewhat expected summer phenomenon, for Nepal heatwaves are raising unprecedented questions about adaptation. “Metal roofs increase the risks of heat,” Pokhrel said. “They need to be replaced with materials which are heat resilient and with increased ventilation. This is more important than giving out sherbets and water during heatwaves,” Pokhrel said. Adaptation pilot projects are underway but heatwave casualties are not being tracked in Nepal, the Maldives or Sri Lanka.
Southasia accounts for 29 percent of the 736 million people living in extreme poverty worldwide. Low-income populations face significantly higher exposure to heatwaves. By 2100, the poorest 25 percent of the world population is expected to be exposed to heatwaves at a rate equivalent to the rest of the global population combined. Many of them will live in Southasia. It is imperative that the region’s governments act immediately to help them.