A word like ‘heatwave’ sounds innocuous—compared to, say, ‘drought’ or ‘floods’. And temperatures are like death counts—after a certain point, numbers begin to lose meaning. What does it mean to live—or die—in ‘extreme heat’—when you’re poor?
A jaw-dropping heatwave
On Wednesday, the Mungeshpur area in Delhi recorded an insane temperature of 52.9°C —the highest ever recorded in India. And only 3.8°C lower than the highest temperature ever recorded on Earth—in Death Valley, California.
Now, it isn’t clear if the recorded temperature was an error—or truly a sign of a climate calamity. The Safdarjung weather observatory—which represents Delhi as a whole—registered a maximum temperature of only 46.8°C. (‘Only’—a word of what is soon going to be the new normal—thanks to global warming.)
But, but, but: A Washington Post analysis shows that haggling over a few centigrades here and there is meaningless. It was dangerously hot in Delhi, period:
A Washington Post analysis found that the wet-bulb globe temperature, which measures the amount of heat stress on the human body, reached 97 degrees to 100 degrees (36 to 38°C) in Delhi on Tuesday. That is higher than the 89.6°F (32°C) threshold that researchers have identified as posing a risk to human survival if such heat is prolonged.
Not just Delhi: We’re all obsessed with the capital, but it was appallingly hot across North India—with several cities recording all-time highs. Example: Rohtak (48.8 °C) Sirsa (49.5°C) Fursatganj (47.2°C) etc.
The climate change picture: Today, 52.9°C may seem like an astonishing anomaly. But these kinds of days may become the norm in India. A single degree of warming will result in 32X as many extreme heatwaves—that last 5X as long.
And how likely is that? A 2020 government report estimates our average temperature will increase by 2.7°C in the next 50 years—if we do absolutely nothing to curb carbon emissions. With moderate curbs, the temperature will still rise by an average of 2°C by 2069—and hit 2.4°C by 2099. So unless there are dramatic interventions, we will blow past that 2°C threshold faster than the rest of the world.
Also this: The warmest day and coldest night by 2100 will be 4.7°C and 5.5°C warmer, respectively. If we’re already at 50°C…
What does ‘extreme heat’ mean, really?
A word like ‘heatwave’ sounds innocuous—compared to, say, ‘drought’ or ‘floods’. And temperatures are like death counts—after a certain point, numbers begin to lose meaning. So what does it mean to live—or die—in a heat wave?
Let’s start with the man who died in Delhi on Wednesday. The 40-year-old from Bihar worked in a pipeline fittings factory. His room did not even have a fan. His body temperature shot up to 107°F (41°C). His roommates brought him to the hospital—but it proved too late. So why did he die?
Total meltdown: When your body heats up, your brain tells your blood vessels at the extremities to dilate. It increases blood flow near the skin—and encourages sweat that cools the body down. It’s a very efficient system but it has limits. When temperatures become “extreme,” then this happens:
Initially, heat increases the body’s metabolic rate: cells consume more oxygen, your heart rate rises, and your breathing grows rapid. As internal heat mounts, enzymes cease to function and proteins become misshapen. An overheated person might experience dizziness, confusion, inflammation, nausea, seizures, or coma. In the worst cases, the body desperately shunts blood to the extremities in an effort to release heat, in the process starving internal organs of oxygen and causing damage to the gut, liver, nerves, and blood vessels.
This is what a heatstroke looks like. Two-thirds of them are lethal—that’s a higher fatality rate than many deadly viruses.
Heatwaves: Who dies?
Of course, the man who died was in the minority—as 88% of Indian households own an electric fan. But fans are unlikely to save Indians from a rapidly warming planet. Power consumption is a privilege in India. So that is a misleading statistic. As Dhruv Khullar notes in the New Yorker: “Only eight per cent of Indians have air-conditioning, and many lack reliable electricity, a situation that limits their use of fans and other cooling devices.”
Always hot, all the time: Most of them toil out in the open—unprotected by the scorching heat. Like Sameer Prakash, sabziwala—who was waiting for his customers outside their air conditioned homes:
He alternates between splashing water on the vegetables to stop them wilting, and on his head to avoid heatstroke. “What’s the choice? No one is going to feed my children unless I take some money home, are they? Work is work. It just has to be done,” he said. “The sun just kills the vegetables so I buy less than usual from the wholesale market because if I don’t sell them, they will rot.”
People like Prakash go back to cramped homes with little cooling or ventilation. The heat during the day strains their bodies—which get little respite at night:
Researchers believe high temperatures at night compound the effects of a day spent roasting in the sun. People’s bodies are forced to work overtime to stay cool. Their sleep is disrupted. Their strained cardiovascular systems are denied a chance to recover.
Living in an oven: The numbers speak for themselves. A Kolkata study found that the heat index—temperature plus humidity—in urban slums was 5.29°C higher than that outdoors. These homes experienced dangerously high heat and humidity (at least 45°C) for nine hours each day. And there was no relief at night: “During the coolest time of night, the insides of urban dwellings recorded a 6.4°C higher heat index than outdoors.”
Heatwaves: What’s the number?
We don’t really know how many people die due to heat waves in India—the numbers are likely as misleading as our Covid death toll:
In 2010, during a heatwave in Ahmedabad, the financial centre of the state of Gujarat, officials counted seventy-six heatstroke deaths during the hottest week—but a later analysis of death certificates revealed that there had been at least eight hundred more deaths than usual during that time, some two hundred of them on a single day.
The official total is just the tip of the iceberg. One reason for this: Heatstrokes are easily misdiagnosed:
Besides neurological impairment, high core body temperature (at least 40 degrees C), or hot, dry skin are other heat stroke symptoms. These may be confused with fever. Clinically, a diagnosis of heat stroke poses a unique challenge as it requires the elimination of other causes of stroke, history of infection, and medication overdose.
The best estimate: According to previous studies, each day the temperature rises above 35°C in India, the annual mortality rate increases by three-quarters of a percent. In comparison, the increase in the US is only .03%.
The global picture: Just as poorer Indians suffer more—so do poorer nations. A 2023 study found that the poorest parts of the world are likely to be 2-5X more exposed to heatwaves than richer countries by the 2060s. By the end of the century, “the lowest-income quarter of the global population’s heat exposure will almost match that of the entire rest of the world.”
The bottomline: Unbearable temperatures will soon make it impossible to labour outdoors—in farming, construction—or in industries that use furnaces—such as metals, glass, plastics etc. Global warming offers a stark choice to the poor—either die working in the sun—or starve at home without wages.
Reading list
The Guardian offers a good overview of the heatwave in Delhi. This dense read in The Hindu lays out the multiple and complex effects of heatwaves. Mint focuses on the effects on the economy. On what it means to be poor during a heatwave, read this Washington Post (splainer gift link) deep dive—which tracks a bricklayer and a delivery worker. This New Yorker piece offered a thought-provoking comparison between climate change in Western countries and India. This Open City report has all the data and charts on climate change in Delhi.
