At large events all over the world, the scenes of extreme heat stress are starting to look familiar. Older men, shirts undone, lying down with their eyes closed. Aid tents packed with the unconscious. And lines of the faithful — whether they seek religion, music, ballot boxes or sport — sweating under slivers of shade.
The consequences have been dire. At this year’s hajj, the Islamic pilgrimage in Saudi Arabia, at least 1,300 people died as temperatures surpassed 100 degrees Fahrenheit. And in many ways, that heavy toll was just the latest sign that crowd control and heat waves fueled by climate change are on a dangerous collision course.
During India’s recent election, dozens of poll workers died on the job. Last summer, troops of Boy Scouts visiting South Korea for a jubilee became sick from heat, as did others at music festivals in Australia, Europe and North America.
Even as heat kills more people today than any other extreme weather event, there is still a dangerous cultural lag. Many major-event organizers and attendees are still behind the climate curve, failing to contend with just how much a warming planet has elevated the risk to summer crowds.
“As the warm seasons get longer, as the heat waves come earlier, we’re going to have to adapt,” said Benjamin Zaitchik, a climate scientist at Johns Hopkins University who studies health-damaging climate events. Along with personal behavior, he added, infrastructure, emergency management and social calendars must “really acknowledge this new reality.”
Among the many low-tech ways to prevent sickness and death are shade, water stations, sidewalks painted white to reflect heat and emergency health services to treat severe cases of heatstroke. Some hot and innovative places, like Singapore, have constructed public spaces uniting the outdoors with the indoors. They have added air-conditioning to areas where people might have to spend time waiting, such as bus stops.
The hardest fix of all may be one that is also in some ways the simplest: educating ordinary people about the risks of heat, including those who are accustomed to living in hot places. Often, they are unaware of the early symptoms of heat stress or how high temperatures are especially dangerous for people with pre-existing health conditions, like kidney disease or hypertension. Even medicines, such as anticholinergic drugs, that treat allergies or asthma can accelerate problems by restricting sweat.
“Heat is a very, very complex and sneaky killer,” said Tarik Benmarhnia, an environmental epidemiologist and associate professor at University of California, San Diego. “It’s very silent.”
A religious pilgrimage can be the trickiest of all events. Devotees of many faiths — Christians in the Philippines; Hindus in India; Muslims in Saudi Arabia — have died from heatstroke in the past few years during religious rituals.
But the hajj carries perhaps the gravest level of danger.
The entire Arabian Peninsula is hot and warming fast, with nighttime temperatures also rising, stealing away the hours when the body usually cools down. Hajj takes place over five or six days, compounding heat exposure in the holy city of Mecca.
The hajj calendar is also set by the lunar cycle, so the scheduled times for the journey could be the hottest, as was the case this year. And because pilgrims tend to be disproportionately old, they are more vulnerable to the effects of intense heat.
Dr. Benmarhnia shuddered when he heard the news of this year’s hajj deaths.
“I thought this could have happened to my grandmother,” he said by telephone Monday.
He had paid for her trip to Mecca in 2019. She was 75 years old, but, thankfully, he said, she went on a smaller pilgrimage during a cooler time, in April. With the death toll this year, he suggested that heat experts use what happened to quickly devise adaptation strategies with religious authorities.
The Saudi Ministry of Health had introduced educational campaigns urging people to stay hydrated and use umbrellas. Officials set up field hospitals and water stations. They deployed thousands of paramedics.
It was not nearly enough for a surge of millions, including many who sidestepped national quotas meant to limit the crowd size. And Saudi Arabia has faced criticism over the deaths for its handling of the pilgrimage.
India’s election this year demonstrated that even in places where people think they are accustomed to heat, much more awareness is needed on the dangers of extreme heat.
In Bihar, at least 14 people died by the end of May, and at least 10 of them were polling personnel, according to the state’s disaster relief officials. At one point in June, nearly 100 people died within 72 hours in Odisha in cases suspected to be linked to heat conditions.
Health officials in India have had to prepare. Inside heatstroke units in Delhi hospitals, patients were immediately immersed in an ice-filled submersion tub to bring down their temperatures. In a ward equipped with an ice-making refrigerator, ice boxes and ventilators, critical patients were immediately placed on slabs of ice and injected with cold fluids.
But in many areas, heat waves and voting peaked around the same time — including in the Aurangabad district of Bihar, home to some three million people, where temperatures approached a desultory 48 degrees Celsius (118 Fahrenheit) in late May.
Ravi Bhushan Srivastava, the chief medical officer at a government hospital, was on his way to assess the daily post-mortem reports on one particularly bad day, when 60 patients were admitted for heatstroke.
“At least 35 to 40 were in a bad condition,” he said. “They were either unconscious, in altered consciousness, with very hot bodies and having trouble breathing.”
“I have never seen patients with symptoms of heatstroke in such large numbers and with such intensity in my entire career,” he added.
Election rallies can be particularly vulnerable, because of the large crowds they involve. But there, too, are plenty of viable solutions. Aditya Valiathan Pillai, an adaptation specialist with the Sustainable Futures Collaborative, a research organization in Delhi, said attendees should be able to see real-time local temperatures, with color-coded risk levels. Water stations, shade and cooling centers can be set up. Not least, public agencies should pull out the stops with earning warnings about heat. “We now have heat wave forecasts that are pretty accurate five days out,” Mr. Pillai said, “so this sort of advance awareness building is possible.”
Sporting events have already been adapting to the dangers of extreme heat. Water breaks for players were introduced during the 2014 World Cup in Brazil when the combination of heat, humidity and sun exposure led to a temperature of 89.6 degrees Fahrenheit. Officials moved the 2022 World Cup in Qatar from the summer months to November and December, when it is cooler.
The Paris Olympics seems to be seeking some sort of balance. Some events, like the marathon, are starting earlier in the day, and water stations are supposed to be available for patrons.
“Mega events like the Olympics and FIFA World Cup have a duty of care to all who attend,” said Madeleine Orr, a professor at the University of Toronto and the author of the book “Warming Up: How Climate Change Is Changing Sport.”
“We’re talking about hydration breaks and cooling breaks,” she added, “opportunities for athletes and officials to access cooling towels and some shade or misting fans, and medical staff on standby to step in should somebody need additional care.”
For now, that may be enough. Many experts say that more radical shifts may need to follow. The Summer Olympics might have to become the Autumn Olympics. Similarly, elections in India may be pushed to cooler months, along with international tennis tournaments. School holidays could be rescheduled for weather. Summer jobs like painting houses may become spring jobs.
David Bowman, a climate scientist in Tasmania who wrote an article that attracted wide attention online during Australia’s 2020 bush fires calling for the end of the summer school holidays, said that people were already beginning to adapt in small ways. Umbrellas are becoming fashionable accessories for shade, shorts are becoming more acceptable at work and road workers are doing more at night.
Climate change could force big events to change even more.
“All these disasters are like a cultural climate change price signal,” he said. “Sure, we can be stubborn and press on regardless of a changing climate — but, in the end, the climate will win.”
Suhasini Raj contributed reporting from New Delhi, and Pablo Robles from Seoul.