Northern India Endures Heat Wave, and a Wave of Deaths

An unusually intense heat wave has swept across northern India in the last four days, with some hospitals in the state of Uttar Pradesh recording a higher-than-usual number of deaths. Doctors there are convinced there’s a link between the punishing temperatures and the deaths of their patients, but officials are investigating what role the dangerous combination of heat and humidity played in the rise in mortality.

In Ballia District, population about three million, the daily high temperature over the same period has hovered around 43 degrees Celsius (above 109 degrees Fahrenheit), nine degrees hotter than usual, alongside relative humidity as high as 53 percent. Dozens of deaths were recorded at hospitals there on June 15, 16 and 17.

Dr. Jayant Kumar, the chief medical officer of Ballia District, near the state of Bihar, said that 23 people died in the district on Thursday. The next day, 11 more succumbed. “The number of deaths has been more than normal,” Dr. Kumar said.

He told the Press Trust of India, a news agency, that on average, eight people usually die per day. “Most of these are natural deaths,” he told The Times in a phone interview, “most of the dead being elderly people suffering from different ailments like diabetes.”

But Indian government officials have pushed back against linking the deaths too directly to the punishing heat.

Dr. Diwakar Singh, formerly the chief medical superintendent of Ballia District, told reporters on Friday night that 34 people had died of heat stroke at the main hospital under his oversight. The next day, he was reprimanded by the state government for prematurely drawing that conclusion and removed from his position.

The government has since sent a scientific team from the state capital, Lucknow, to investigate the causes.

Dr. Singh’s replacement, Dr. S.K. Yadav, took a more cautious line on Sunday, saying, “Elderly patients with comorbidities like hypertension and diabetes are expiring because of heat.”

“Still,” he added in a phone interview, “the death numbers are more than normal.” He agreed with Dr. Kumar’s assessment that the excessive heat was to blame for the high death toll, whatever the exact link.

While an extraordinary number of patients were being admitted for heat-related distress, Dr. Yadav said, “we are able to provide beds to all the patients, and we have enough doctors and medicines.”

The nightmarish prospect of mass deaths caused by a sudden rise in temperatures has become more urgent in recent years. And the phenomenon in this area of the world may portend a warning beyond India’s borders.

The heat in this part of India has been hovering around the critical “wet-bulb temperature,” the threshold beyond which the human body cannot cool itself to a survivable point by perspiration, defined as 35 degrees Celsius (95 degrees Fahrenheit), adjusted for 100 percent humidity. The wet-bulb reading in Ballia on Saturday reached 34.15 degrees Celsius (about 93 degrees Fahrenheit).

It is expected that more older or infirm patients than usual will die in heat waves like this one, which climate change has made more common across India’s historically scorching plains, as in most of the world, scientists say.

The question is whether these are “excess deaths,” of the kind that can be measured only statistically, or whether India’s incrementally more unbearable weather is playing a more direct role in causing them, for instance by heat stroke. When more deaths are recorded than were expected, they count as excess. But that leaves open the question of what exactly caused them.

Local newspapers, collecting figures from different officials and hospitals, have counted as many as 54 deaths in Ballia and an additional 44 in Bihar over the past three days.

In April, when temperatures in the western state of Maharashtra were nearing their peak, at least 11 people are known to have died of heat stroke almost simultaneously.

An especially humid city like Kolkata now crosses the anticipated limit of human survivability to heat with only perspiration for cooling several times a year; some epidemiologists are puzzled that more Indians do not drop dead of heat.

The fact that wet-bulb temperatures in much of South Asia have been inching nearer to the critical level has provoked global concern over the past few years. It has even made its way into literature. “The Ministry for the Future,” a science fiction novel written by Kim Stanley Robinson in 2020, imagines a scenario in which 20 million Indian citizens living in the same part of the country — men, women and children — are killed by an intense heat wave within one week, immediately changing the course of history.

The region’s hottest weather breaks in June every year. A cyclonic storm, the Indian Ocean equivalent of a hurricane, pushed through India’s western coast late last week, and its rains are expected to arrive in Uttar Pradesh and Bihar within the next two days. That should bring temperatures down from their highest level. Soon after, the region can expect the annual monsoon.

The diagnosis by the medical team from Lucknow that is analyzing last week’s excess deaths may not mention heat stroke. In that case, it will most likely describe a situation like the deadly heat wave that hit Chicago in July 1995, which was blamed for killing 700 people, or the one that caused tens of thousands of deaths in Europe in August 2003.

What is not in doubt is that weather of the kind that is becoming increasingly commonplace on every continent is making greater numbers of people die sooner than they would have in cooler times.