In the summer, you can see the heat. It looks like a wraith and feels like your double. In 2018, the Indian Meteorological Department (IMD) predicts, all parts of the country will have an intense summer, with the prospect of heat waves hitting much earlier and continuing late into the season.

Summer arrived early, in February, with temperatures reaching 2C-5C above normal. The maximum and minimum temperatures of the month were around 3C above normal.

Between March and May, maximum temperatures in some parts will exceed the normal by less than 0.5C, some by 0.5-1 C, and some above 1C. So the core heat wave zone will be hit especially hard.

IMD’s “Seasonal Outlook for the Temperatures during March to May 2018”, predicts warmer than normal temperatures in all meteorological sub-divisions. Normal to above normal heat wave (HW) conditions are likely over the core heat wave zone of Punjab, Himachal Pradesh, Uttarakhand, Delhi, Haryana, Rajasthan, Uttar Pradesh, Gujarat, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, West Bengal, Odisha and Telangana and the subdivisions of Marathwada, Vidarbha, Madhya Maharashtra and coastal Andhra Pradesh.

For the last few years it’s been getting hotter earlier in the season. It’s remaining hot for a longer time. Extremely hot days are increasing in frequency. Every year, every month in most parts of the world, record high temperatures seem to be the norm. Since modern record-keeping began in 1880, 17 of the 18 hottest years have occurred since 2001. Global mean temperatures have increased by 1C since the industrial revolution.

Heat has wide-ranging impacts on human health, directly and indirectly. An article by Tracie White in Stanford Medicine Magazine in 2007 gives the anatomy of heat-related death: “It can take only 48 hours of uninterrupted exposure to intense heat before the body’s defences begin to break down...

Extreme heat is a health hazard at many levels. Apart from exhaustion and heat stroke as well as cardiovascular and respiratory complications, it indirectly increases the chances of water-and-food-borne diseases.

“Dehydration at high temperatures… causes the sweating mechanism to fail, eliminating the body’s natural cooling system. Body temperature may rise to 106F or higher in just 10 to 15 minutes. Heat stroke begins when people start to develop an altered level of consciousness, usually temperature above 105. Then the body starts to cook. First the brain cells die. Then the liver cells go. Fluid spills out into the lungs. If the body remains in the zone, the result can be coma and, finally, death.”

The longer a heat wave continues the more susceptible the body becomes to illness, the article continues. “Just a few hours of relief can break the cycle, which is why increased temperatures at night are so dangerous...”

Extreme heat is a public health crisis and hazard at many levels. Apart from exhaustion and heat stroke as well as cardiovascular and respiratory complications, it indirectly increases the chances of water-and-food-borne diseases, says Shubhayu Saha. Assistant professor at the department of environmental and occupational health at Emory University, U.S.

Kolkata-born Saha works on the wide-ranging impacts of extreme temperatures on human well-being and policies that help individuals and communities cope with these conditions.

Hot and humid conditions encourage propagation of malaria, dengue, and chikungunya, he says.

“Higher temperatures, in conjunction with humidity and rainfall would be conducive for mosquitoes to change habitat, propagate and change the distribution of some infectious diseases.”

The fact is that we live in a climate hotter than we’re used to.

Our built environment—infrastructure, for example—is not designed for such temperatures. Asphalt roads can melt; in the last three years, rail tracks buckled in intense heat. Heat can affect the structural integrity of materials.

The high homicide rate in summer is thought to be heat related.  Researchers in the West used the General Aggression Model, which posits that hot temperatures make people irritated, and thus hostile to other people. Another theory—Routine Activity Theory—holds that in hot weather people stay out of doors and interact more, which increases the chances of conflict. (To put the theory in the Indian context, more violence will occur at 40C than at 35C).




new model, called CLASH (Climate Aggression, and Self-control in Humans), published in the Behavioural and Brain Sciences, suggests that a hot climate and lower variations in temperature between seasons makes people focus on the present at the cost of the future, and lack self-control, which leads to more aggression and violence. No such India-related studies exist, unfortunately.

A 2017 study, published in the Proceedings of the National Academy of Sciences of the United States (PNAS) analysed data on 12 million Americans born between 1969 and 1977. It found “adult economic outcomes are negatively correlated with prenatal exposure to days with mean temperatures exceeding 32C.”

The authors say foetuses and infants are “especially sensitive to hot temperatures because their thermoregulatory and sympathetic nervous systems are not fully developed.”

“We find that an extra day with mean temperatures above 32C in utero and in the first year after birth is associated with a 0.1 per cent reduction in annual earnings at age 30. Temperature sensitivity is evident in multiple periods of early development, ranging from the first trimester of gestation to age 6–12 months,” the authors say.

India’s political and institutional inertia feed into the crisis;  no ambulances for people when they drop from heat, doctors not available in government hospitals and people can’t afford private medical care.

Another American study found “dementia and schizophrenia are significant risk factors for heat-related hospitalisation.” An emerging field of research links extreme heat to chronic kidney disease (CKD). A 2016 paper published in the Clinical Journal of the American Society of Nephrology says, “Recent studies have shown that recurrent heat exposure with physical exertion and inadequate hydration can lead to CKD that is distinct from that caused by diabetes, hypertension, or GN (glomerulonephritis). Epidemics of CKD consistent with heat stress nephropathy are now occurring across the world.”

The paper states that “an epidemic of CKD in rural farmers (of rice, coconuts, and cashews) in Andhra Pradesh, India... A study of 1500 villagers in the Prakasam district documented 27 per cent with serum creatinine levels greater than 1.5 mg/dl... Studies based on sites where hemodialysis is present suggest even higher rates in Nellore district to the south, and represent rates that are about tenfold higher than in other regions of India.”

The paper states: “Other areas with CKD of unknown etiology are slowly being recognised. For example, there are reports of CKD epidemics in other areas of India, including Goa, some regions in central Odisha, and Akola district in Maharashtra. This seems consistent with increased occurrence of heat waves and decreased rainfall in these regions.”




ccording to Saha, “Extreme heat not only has direct health consequences, but can lead to failures in the energy and agriculture sector that have adverse consequences.”

For example, he continues, “Greater electricity demand during extreme heat could lead to failure in power supply in urban settings that can compound the public health crisis; crop failures coupled with prolonged droughts impact agricultural communities.”

India’s socio-economic-cultural context and political and institutional inertia feed into the public health crisis;  no ambulances ferry people immediately when they drop from heat stroke, doctors are not available in government hospitals as required and people can’t afford private medical care.

People are far more undernourished and anaemic. There is water scarcity (3 per cent of potable water for 20 per cent of population). A quarter of the population—300 million people—don’t even have a power connection. So there is no AC or fan to cool things.

Many of those who have power do not have regular supply; many houses (slums and villages) have no separate kitchen. People use dung cakes or wood for cooking—filling the already hot, dark tin roof shacks with  smoke; women wear saris, blouses and petticoats and walk miles to carry small quantities of water.

Without a bathroom they can’t shower to cool themselves, without an indoor toilet they can’t even relieve themselves indoors and avoid going out in the daytime. They perhaps intentionally dehydrate themselves by not drinking water to avoid going out. People work outdoors in the sun, increasing their risk, even if it’s not their choice as they have to earn a living.

India doesn’t have a nationwide system of heat alerts and warnings. And low education and literacy rates mean that heat warnings wouldn’t be understood. Last but not the least, institutions don’t have, collect or share data so scientists can’t even do research and bring out these issues.



xtreme heat is one of the results of global warming. Heat waves will continue to get more intense, more frequent, and last longer as the planet heats up. The weather events now occurring take place in an altered climate. Higher mean temperature is the springboard, accentuating their power. What we have is the result of an energy imbalance in the system.

Oceans are taking up the excess heat trapped by greenhouse gases, and are warming up. A 2018 study in Advances in Atmospheric Sciences by Lijing Cheng and Jiang Zhu states that 2017 was the warmest year on record for the oceans.

“The warming is global and (the accumulated heat) is the memory of past climate change,” says Kevin Trenberth, the head of climate analysis at the National Center for Atmospheric Research in Colorado, explains in an email.

Warm water expands, rises, and floods the coasts. According to another 2017 paper in Science Advances, and commentary in Earth and Space Science News (EOS)—Trenberth is a co-author of both—not only have oceans warmed but  the pace of warming has nearly doubled since 1992 and has reached deeper layers.

“The increase in ocean heat content observed since 1992 in the upper 2,000 metres is about 2,000 times the total net generation of electricity by U. S. utility companies in the past decade,” the authors of the EOS commentary say. 

Earth’s energy imbalance, ocean heat content and sea level rise are so linked that as much as 50 per cent of the global sea level rise is due to warming. It has also scrambled the oceanic food chain.

“Water is the air conditioner of the planet,” Trenberth says. “Extra heat goes into evaporation if water is available. If not, as in drought, the temperature really goes up.  The energy imbalance for the planet is about 1 watt per square metre. Globally, that is about 1,000 times  all the electrical energy generated every year. In the absence of water, this heat accumulates so that over a month it is 720 watts per square metre for 1 hour:  720 watts is the power of a small microwave oven. The atmosphere demands more moisture because it is warmer, but it is the plants and soils that end up drier: increasing the risk of wild fires. No wonder things catch fire!”

 If there’s water available it mitigates this, he continues. “But the energy accumulates in the ocean. The ocean is warmer, and the air above the ocean is warmer, more moist than it used to be. This is the dominant influence of climate change. The moisture is gathered up by storms and it leads to heavier rains. ”




eat waves typically hit India between March and June and if the monsoon is delayed could extend to July in rare cases. North India gets five to six heat waves a year, with temperatures going up to 46C in some parts. Central and north India are the worst affected.

According to IMD’s Forecast Demonstration Project (FDP) for improving heat wave warnings report for 2017, except for the northeast and parts of peninsular India, most areas experienced more than or equal to two heat waves. Punjab, Haryana, parts of west and east Rajasthan, Madhya Pradesh, Chhattisgarh, Vidarbha, west Uttaranchal, east Uttar Pradesh, western Jharkhand and Bihar, Gangetic West Bengal, northern Odisha, Telangana, coastal Andhra Pradesh, eastern Rayalaseema and north Tamil Nadu on average experienced eight or more heat wave days.

The heat waves come in two types, according to a 2016 paper in Nature Scientific Reports. Lead author J. V. Ratnam at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), explains in an email: “The first-type over north-central India is associated with disturbances from the higher latitudes. Disturbances favour transport of heat from the desert or northwest India into other parts of India.”

“The second type,” Ratnam continues, “of heat waves over the coastal regions are related to conditions in the west Pacific. During the type 2 events, the winds are such that they cut off the sea-breeze, which is the main source of cooling for coastal areas.”

Another Ratnam paper, published in 2016 in Nature Scientific Reports, talks about two types of cold waves over India: The first, the dominant one, covers most of the country with colder than normal temperatures, while the second type is more regional, only noticeable over northwest India.

Ratnam is working on improving the forecast of heat waves at seasonal timescales.

  “During the 20th century, central India warmed severely compared to other regions. The observed warming is more pronounced in the summer followed by winter, monsoon season, and post-monsoon.”

A number of studies point to warming over India and the competing effects of greenhouse gases and aerosols. According to a study by Shaik Ghouse Basha and M. V. Ratnam from the National Atmospheric Research Laboratory, Tirupati, Andhra Pradesh, in Nature Scientific Reports, surface temperatures over India rose by 0.85C between 1860 and 2015. They looked at the relative contribution of external inputs such as natural (solar radiation, volcanic emissions) (NAT) and human (greenhouse gases, GHG, anthropogenic aerosols, AA, and land use, LU).

“Human activities are highly responsible for the increase in warming over India… predominantly attributed to GHG followed by LU. A sharp increase in warming is noticed from the 1960s onward from GHG, whereas LU increase is observed from 1980. The impact of GHG is high over northern and western parts of India,” Basha and Ratnam explain.

“During the 20th century, central India warmed severely compared to other regions. The observed warming is more pronounced in the summer followed by winter, monsoon season, and post-monsoon.”

While greenhouse gases ramp up warming, aerosols—fine particles floating in the atmosphere—mask the effect of greenhouse gases.

Arpita Mondal at IIT Bombay is studying the impacts of climate change with a focus on hydroclimatic extremes. As part of the interdisciplinary programme in climate studies at IIT Bombay, she and aerosol science expert Chandra Venkataraman are studying the link between aerosols and climate change. They are trying to analyse the role of anthropogenic aerosols on long-term changes in seasonal rainfall, as well as pre-monsoon high-temperature heat-wave type events. The study is not published yet.

Particulate pollution includes black carbon from burning solid fuel, dust, sulphates from burning fossil fuels, nitrates, ammonia, soot, and other compounds. They remain in the atmosphere for one to four weeks, and eventually form the nuclei of rain drops. The black carbon, studies show,  is the second-most important driver, next only to carbon dioxide, of climate change.

In most world regions, aerosols are believed to have an overall cooling effect, offsetting global warming. Mondal says that is true of scattering aerosols, not “absorbing aerosols” such as black carbon and dust found in abundance in India and China.

People in many parts of north India and the Gangetic plain use firewood and coal as fuel for cooking or burn biomass outdoors. Incomplete burning of such fuel releases  black carbon into the atmosphere. Using chemistry-coupled climate model simulations, Mondal, Venkataraman and team find that the black carbon and dust concentration is particularly high in the atmospheric layer close to the surface, during the heat-wave type events in north-central India in the pre-monsoon season. More incoming solar radiation is trapped in the atmosphere by absorbing aerosols, “leading to a higher heating rate of 0.33 Kelvin/day on average, as compared to the normal 0.26 Kelvin/day. These conditions also coincide with large-scale atmospheric conditions that favour heat waves.”

While the effects of absorbing aerosols are well-known, their analysis links it to heat waves.

“The presence of absorbing aerosols influences the fluxes of heat, and the incoming and outgoing radiation to and from the earth’s surface,” Mondal says.

The study also looked at satellite observations of absorbing aerosols in the month of May in 2015, when a massive heat wave killed around 2,000 people in the country. It found the absorbing aerosol index to be significantly higher in north India compared to the long-term mean.

“On the one hand, there’s direct health impact of aerosol pollution in the short term, on the other, there are long-term changes in the climate. Both need to be studied well,” she adds.

Another phenomenon being studied is atmospheric stagnation. A 2014 study in Nature Climate Change by Daniel Horton, assistant professor at Northwestern University, Evanston, Illinois, U.S., and his team analysed atmospheric stagnation events, the meteorological condition that allows pollutants to accumulate in the near surface environment, Horton explains in an email.

Pollutants accumulate when there are no (or light) winds, no rain to wash them away. The U. S. National Climatic Data Center uses a metric called the Air Stagnation Index (ASI), which indicates that a given day is stagnant when surface winds are light, upper atmosphere winds are light, and there is little to no precipitation.

 In their study, Horton and his team used an ensemble of climate models to better understand the frequency of stagnant conditions in our current climate, and to determine how the characteristics might change in a future high GHG emission scenario.

In the hill states of Uttarakhand, Himachal Pradesh, and Jammu & Kashmir, summer temperature departures are around 7-8C higher. But winter temperatures are also rising.

“Average winter temperatures have increased in the last two years by 2-3C in Uttarakhand, Himachal Pradesh and Jammu and Kashmir mainly due to the subdued activity of western disturbances. 

“We found that changes in atmospheric circulation and the hydrological cycle could increase stagnation in several regions of the world, including many with pre-existing air quality issues,” says Horton.

The study found that in a situation where green house gas emissions are high, large parts of India, Mexico, and the Amazon will be affected, several times over than what’s happening at present.

“Stagnant conditions can be similar to the meteorological conditions that produce heat waves. The combined impact of simultaneously occurring heat waves and degraded air quality can have calamitous effects on public health, and is particularly problematic for those who are most vulnerable, children and the elderly,” says Horton.




n the hill states of Uttarakhand, Himachal Pradesh, and Jammu & Kashmir, summer temperature departures are around 7-8C higher. But winter temperatures are also rising.

“Average winter temperatures have increased in the last two years by 2-3C in Uttarakhand, Himachal Pradesh and Jammu and Kashmir mainly due to the subdued activity of western disturbances. This leads to less snow and ice, and helps more sunlight to penetrate, thereby amplifying the warming. More warming leads to more melting,” says Akshay Deoras, meteorologist and independent weather advisor to the government of Maharashtra.

A graduate in climate and atmospheric science from the University of Leeds, UK, his research interests include the monsoon and western disturbances. He helps farmers through an NGO by issuing forecasts and other weather-related events.

This ice-albedo effect (when there is less of it), Deoras says, explains the significant warming in summer months when temperatures are often 4-6C above normal in these states. All this is tricking flowers like the Himalayan Rhododendron to bloom earlier in these areas.

Conventional wisdom has it that paved roads (and the use of air conditioners) reflect and trap more heat in urban centres, giving rise to urban heat islands. But a 2017 study in Nature Scientific Reports, says rural India suffers most in the heat. In the post-harvest season they are denuded of vegetation and parched, increasing the heat stress for people. Moreover, urban centres have amenities that can be accessed in an emergency, which rural areas don’t have.



eople drop dead, just like that in the heat,” says Pattapagalu Venkata Rao, head of the rotary committee that manages two burial grounds (Rotary Kailasa Bhoomi) on the banks of the Godavari in Rajamahendravaram in East Godavari district of Andhra Pradesh. He should know, for he has been at it for 27 years.

He gets, he says, 30 bodies a day for cremation or burying (80 per cent are for cremation) for the two grounds.  But seasonal deaths are a different matter. In summer, he gets 70-100 bodies a day.

“I have observed in December-January, and April to June, deaths are more. It starts from April 10-15, exactly, and goes higher and higher.”

“Cremate or bury, cremate or bury”—that’s how it goes in summer. He plies vehicles in the summer and his staff pick up unclaimed bodies of beggars, and people in old-age homes. People from different parts of the Godavari districts and from afar bring their dead relatives.

The climate has changed, he says. “Water in the Godavari is less, forests are gone; our places are filled with tar and cement; we have ONGC wells and gas projects nearby,” he says.

Summers keep Rao harried: “When I go there (to the grounds) at 5 a.m., the dead are waiting. I have no holiday; I get only 2-3 hours of sleep; my people attending to the pyres get scalded; drivers don’t turn up because of heat; I have to manage all these things. I have my own troubles.”

Even if one is not dead yet, the humidity can make you feel like a wet rag on a clothesline, hung out to dry. What’s more, the rag won’t dry out quickly in the prolonged spells of muggy hot days.

Our bodies thermoregulate and come to equilibrium by shedding the excess heat between our core temperature—from top of head to mid-chest, comprising brain, lungs, and chest—of 37C and skin temperature of 35C. Sweating helps cool the skin, and evaporation gets rid of excess heat. Thus equilibrium is maintained.

If the surrounding air is dry (less water), sweat evaporates fast, thus cooling the skin. If it’s already saturated with high water content (very humid), the air cannot take any more water, short-circuiting cooling mechanism and causing overheating of the body. The combined measure of temperature and humidity is called wet bulb temperature (WBT).  It’s a measure of how much cooling can occur due to evaporation (or perspiration).

According to a 2017 study in Science Advances by Eun-Soon Im Jeremy Pal, and Elfatih Eltahir, the upper limit of wet bulb temperature for human survivability is 35C. In the high emissions scenario, “the WBTs shoot up to and in some cases exceed 35C over many regions of South Asia, including the Ganges river valley, north eastern India, Bangladesh, northern Sri Lanka and the Indus valley of Pakistan. In the mitigation scenario, life-threatening conditions above 30C will happen. According to the U.S. National Weather Service, WBT above 30C is very dangerous.

“India is at the frontlines of global heat stress and the more we can publicise the heat impacts there, the more likely people will be to see the importance of this threat,” Sherwood says.

“Wet-bulb thermometers have been used for over a century to measure humidity. They are just thermometers with wet cloths over the bulb. The temperature you get is the wet-bulb temperature.  Nowadays they have largely been replaced by newer technologies but wet-bulb temperature is still occasionally used as an index of heat and humidity,” says Steven Sherwood, a professor at the climate change research centre at the University of New South Wales, Australia.

Sherwood and Huber proposed the concept of human survivability threshold based on wet-bulb temperature.

“With all the impacts from global warming, whether sea level, heat stress, rains and floods, etc., a similar principle applies. The average gradually changes, and extreme fluctuations due to weather all get lifted with the average. Many can then become more extreme, and eventually unprecedented. It is the unprecedented extremes that should scare us the most, but tends to be talked about the least—usually we just say that there will be more heat waves, when we should be saying they will get hotter.”

Based on the growing scientific evidence, extreme temperature and rainfall events will increase because of climate change.

“India is at the frontlines of global heat stress and the more we can publicise the heat impacts there, the more likely people will be to see the importance of this threat, which will eventually affect many more areas besides India,” Sherwood says.




o many environmental changes are taking place simultaneously in the region that some of them cancel others out in their impacts, while others reinforce the impact. India has seen widespread agricultural expansion and intensification through irrigation. Vast swathes of land, which were previously forest, have been converted to agriculture.

“Intensification of irrigation, most extreme in the Gangetic plain, has a strong cooling effect on surface temperature. Without this irrigation, there would likely be a net warming with agricultural expansion,” Deepti Singh says. She is a climate scientist at the Lamont-Doherty Earth Observatory of Columbia University.

“For South Asia,” she continues, “we find irrigation tends to have competing effects on monsoon rainfall relative to simply considering the effect of conversion to cropland. These impacts are generally consistent during pre-monsoon and monsoon seasons.”

Several studies in the last decade have demonstrated that cooling associated with irrigation tends to weaken the monsoon during the peak of agricultural activities, when it is most needed.

Then there are aerosols and greenhouse gases associated with human activities; the former can mask the effects of the latter. So we have increasing irrigation, extensive land-use changes, and increases in aerosols and greenhouse gases. In her ongoing project, Singh and her colleagues want to “understand how the effects of agricultural expansion and intensification compare with the effects of greenhouse gases and aerosols, across major agricultural regions worldwide.”

Based on the growing scientific evidence, Singh thinks extreme temperature and rainfall events will increase because of climate change. Warming enhances the intensity of rainfall which could lead to increased risk of flooding. It simultaneously increases the risk of dry spells by up to 5-10 days by the end of the 21st century. Even with moderate levels of warming (1-2C), the risk of historically hottest events could increase 3-5 times in the next few decades.

Since the kind of extremes that take human life have become more frequent due to global warming and will increase in frequency, she thinks plans to manage a multitude of extreme events are required. Then there is the case of rising night temperatures, which make it harder for our bodies to recoup from extremely hot days.

“We have to prepare for societal impacts, too,” she says.

A February 2018 paper in Science Advances—of which Singh is a co-author— says human-driven climate change has already increased the probability of record-breaking hot, warm, wet, and dry extremes. This increase in probability is detectable over most parts of north America, Europe, and east Asia. Of particular relevance to India is the concern that even within the Paris Climate Agreement target to keep global warming to within1.5C above the pre-industrial, there are large increases in the risk of historically hottest days, warmest nights, and wettest days across much of the subcontinent.

“We haven’t truly seen the full effects of greenhouse gas warming over India yet due to the masking from aerosols (from fossil-fuel burning)” she says. It’s the poor who are more vulnerable. So, “we have figure out measures to keep them safe.”

It’s not all doom and gloom, though. A 2017 publication in the International Journal of Environmental Research and Public Health by Gulrez Shah Azhar who worked with Public Health Foundation of India, Ahmedabad, and now a researcher in the U.S. (Saha is a co-author), tries to assess and map vulnerability to heat waves across India. This helps policy makers focus on where intervention is needed most. The hallmark of this first-of-its-kind work is that it includes rural areas as all the previous work focuses on urban areas.

“We need to acknowledge that heat is a problem and that it’s not going away,” says Gulrez.

Reviewing the literature for variables that affect vulnerability; demographic (age, sex), social (caste, education), economic (income, household amenities), environmental (green cover, water, sanitation) and drawing upon data from Census 2011, DLHS, ISRO satellite maps for these variables for each of the 640 districts, Gulrez applied statistical techniques---Principal Component Analysis---to reduce their dimensions and combined them to estimate a heat vulnerability index for India. Then, he used this index to rank, map and identify the most heat vulnerable districts. Ten districts show very high vulnerability, most of them in Madhya Pradesh and Chhattisgarh.

Gulrez is working on deaths that could occur in different climate change scenarios using econometric methods and wants to estimate economic costs using Value of Statistical Life estimates.

In addition, PHFI is working on heat action plans for different cities. Mumbai, Nagpur, Surat, and Hyderabad have adopted those plans to varying degrees. A meeting of SAARC countries has recently been held to address the heat-related health crisis.

We need robust scientific assessments for as many locations as possible, Saha says. Since people in different locations are accustomed to different ranges of temperature, contextualising heat stress for individuals and individual communities at the local level will help.

“We need teams of meteorologists and epidemiologists to find the thresholds of ambient temperatures at the local level, beyond which people suffer,” says Saha.

These assessments will provide critical information to planners, public policy experts and social workers to translate this into actionable policy. Already, he continues, expertise exists in meteorology and in public health. “With political will and institutional support, all different agencies can be brought together. Of course, it’s easier said than done.”

Perhaps, “our people will be forced to acknowledge the crisis.” Governments, he says, could see how heat action plans (where  adopted) are mitigating heat-related suffering at low-cost and factor in doing the same for their states.

Regarding the short-term, this summer, with IMD’s prediction of severe heat, he suggests more awareness through media, enquiring about loved ones on a day-to-day basis, and sticking to precautions.

“Heat is an individual and societal problem now.”