(Bloomberg) -- Just before Ana Clara Benevides lost consciousness, she likely found it hard to breathe. 

Packed with 60,000 people in Rio de Janeiro’s Nilton Santos Stadium for a Nov. 17 Taylor Swift concert — amidst a heat wave with a “real feel” of 138F (59C) — the 23-year-old would have been unbearably thirsty, her heart beating fast, her skin hot. Benevides fainted as Swift sang “Cruel Summer,” the second song of the set. Four hours later, she would be dead from heat exhaustion.

Benevides’s death, during a record hot austral spring that researchers later attributed to climate change, made international news as a tragic anomaly. Nilton Santos Stadium, Taylor Swift’s team, and T4F Entretenimento SA — which promoted the event — did not respond to requests for comment.

But Swift’s show came on the heels of other instances of extreme weather harming people at outdoor concerts. During a heat wave last July, 17 people were hospitalized for heat-related illnesses — including two cardiac arrests — at an Ed Sheeran show in Pittsburgh. A month earlier, 100 people were injured by hail at a Louis Tomlinson concert in Colorado’s Red Rocks Amphitheater. 

Taken individually, each of these events can seem like bad luck — part of the vagaries of nature. But stitched together, a clearer pattern emerges: Climate change is ushering in more extreme weather worldwide, and with it, greater risks for outdoor events. Many venues, organizers and fans are ill-prepared. 

“The people who are putting on these events need to have incredibly detailed and well-thought-through emergency plans,” says Catherine Strong, an associate professor of sociology at Australia’s Royal Melbourne Institute of Technology who specializes in popular music studies. “What some of these events are showing is that that isn’t always the case in the way that it needs to be.”

Stuck outside with nowhere to go 

Outdoor events are subject to the whims of weather, but last year’s Louis Tomlinson concert shows how easily an event can go awry.

Red Rocks, which is owned and operated by the City and County of Denver, contracted with Skyview Weather for forecasting during the June 21 concert. At 5:01 p.m., Skyview issued the first of roughly a dozen notifications about storm risk, according to a timeline obtained by the local news outlet Denverite via an open records request. At 7:53 p.m., Skyview declared a 60- to 90-minute lightning risk. Eleven minutes later, Red Rocks displayed its first message telling patrons to seek shelter. 

“I didn’t leave personally, because they didn’t make it seem like it was that big of a deal,” says Allie Arrington, a graduate student at the Colorado School of Mines who attended the concert. “‘You can seek shelter in your vehicle and can return when the show resumes,’” she reads from a photo she took of the warning. “I don’t think many people left that first time.” 

At 8:30 p.m. Skyview cleared the lightning risk, and the concert’s opening acts took the stage.  But by 8:58 p.m., the lightning was back. At 9:09 p.m. another weather alert went out. This time, Arrington headed to her car. “By the time I made it from my seat to the stairs, it was hailing marble-sized hail,” she says. “It was maybe two, three minutes past when they sent out the second warning.”

By the end of the night, more than 100 people would sustain injuries either from the hailstones or in the race to seek shelter from them. Tomlinson never took the stage.

Arrington was able to shelter in the visitor center, but others weren’t as lucky. Most “large outdoor stadiums do not have the capacity to shelter the number of people that can fit in their bowl, indoors or in a safe, covered shelter location,” says Sam Young, a crowd manager who posts about her experiences on TikTok under the name youngsamistic. (Young is not her last name, but the name she prefers to use online to protect her clients.) 

Many outdoor venues assume that a significant number of people can take refuge in their cars if needed. But that assumption can be problematic: Arrington drove two women to their hotel after hail destroyed their front and rear windshields. 

The warnings at the Tomlinson show also came too late for most attendees to get to their vehicles. Arrington estimates her car was a 15-minute walk away, but she didn’t even have enough time to leave the venue. Red Rocks’ website states that “routes from parking lots to the gates may be partially dirt, uphill and sometimes lengthy in distance.”

Red Rocks, Louis Tomlinson’s team and Skyview did not respond to requests for comment. Live Nation, the tour’s promoter, directed Bloomberg Green to the artist and venue.

A confluence of risks 

What happened at Red Rocks was dangerous, but staying out of harm’s way mostly meant staying out of hail’s way. Extreme weather can also create cascading risk, when one hazard triggers another, says Milad Haghani, a senior lecturer in disaster risk at the University of New South Wales.

“One risk leading to another risk, if it’s not adequately planned for, is something that you need to consider,”  Haghani says. 

Last August near Washington, DC, lightning risk led to Commanders Field (then FedExField) declaring a shelter-in-place order during a Beyoncé concert. The two-hour delay left many people stranded outside the venue, while inside so many fans crowded concourse areas and ramps that several had to be treated for heat exhaustion. 

It risked becoming a “crowd crush situation,” Haghani says, referring to a phenomenon where so many people are squeezed into a tight area that breathing becomes difficult. Crowd crushes killed 10 people during a Travis Scott show in 2021, as well as 125 people at an Indonesian soccer match in 2022 and 159 people during Halloween festivities in Seoul that same year. 

Concerts can increase that risk by increasing crowd density, as athletic fields are often converted into standing or seating room for ticket holders. General admission tickets, which guarantee entry but no specific seat, also increase crowding and can reduce concert-goers’ willingness to give up their spot. 

“General admissions is one of the hardest things to manage,” says Rebecca Wilusz, assistant director of athletics at Duke University, home to Wallace Wade Stadium (capacity:  40,000). “People are like, ‘I got here at 6 a.m. to make sure that I would get the spot I wanted. And now you're telling me I have to leave?’”

Dense crowds are more dangerous when it’s hot. Heat taxes the body, puts pressure on the heart and can make breathing difficult. Even modest temperatures can be risky. “Those fall days where it may be 45°F in the morning but it’s 70° by the time the  game starts ... You’re baking in the sun and you’re in the same wool sweater,” says Wilusz. “Now you become a heat patient in November.”

At the Taylor Swift show in Rio, people in the general admission area said it was hard to push through the crowds when they needed air, and difficult for vendors selling water to reach them. At one point during the show, Swift stopped performing to point out fans in need of water; at another, she chucked bottles into the crowd. 

Developing a preparation playbook

Many of the threats to outdoor events are growing with climate change. A century and a half of burning fossil fuels has led to a hotter climate than at any other time in human history. Warmer air holds more water, creating stronger storms. In the US Midwest, climate change has made storms with severe winds five times more likely since the 1980s. Last year, wildfire smoke led to cancellations of concerts and sporting events across the US and Canada.

There are steps venues can take to minimize the dangers. At Duke, a 38-year tradition of camping out in front of the basketball stadium to secure admission to key games now comes with thresholds for temperature and lightning. Once they’re crossed, campers must vacate but don’t lose their spot in line. “There’s a lot of communication and coordination that goes into it,” says Wilusz.  

Duke also evacuates its football stadium if there’s a lightning strike within eight miles (13 kilometers) of campus, which Wilusz says leaves enough time to clear the area and for people to take shelter. To help with its decision-making, the university uses a weather app and a weather service, and has access to an on-call meteorologist. 

Mishawaka, an outdoor amphitheater in Bellevue, Colorado (capacity: 1,000), also has a storm playbook. If there’s lightning within 10 miles, the venue activates a pre-evacuation phase that includes calling in the school buses used to shuttle people to and from its parking lot. The buses can provide shelter, says Mishawaka Operations Manager Will Reutemann, and can also deliver patrons to their cars or to a restaurant on the property.

Florida’s Daytona International Speedway was redeveloped in 2016, and is another example of designing with fan safety in mind, says Kevin Kloesel, an event safety meteorologist at the University of Oklahoma who has studied the racetrack. There was “a really close call with a tornado in 2014,” Kloesel says, after which it “did an entire reconstruction.” Today 100,000 people can shelter on-site.

To the extent that there’s a push among venues to improve safety at outdoor concerts, it can be traced in part to an August 2011 Sugar Land concert at the Indiana State Fair, says Neil Huff, managing director of insurance brokerage Taylor & Taylor Associates. Seven people died and 58 were injured after severe winds toppled the concert’s main stage, leading to a $50 million settlement in 2014. Huff calls it the “granddaddy” of modern event safety case studies. 

The Event Safety Alliance (ESA), a nonprofit that works on best practices in the industry, traces its own origins to the Sugar Land concert. “This was not a group that didn’t have a plan; they just didn’t have the meteorological expertise to execute the plan,” says Kloesel, the ESA’s lead meteorologist. “A person came on stage and actually said to the individuals in the crowd, ‘We can see this coming, we hope it will miss us,’ right? Hope is not a plan.”  

The ESA put out its first weather safety guidelines for events in 2014, and has since worked with the Entertainment Services and Technology Association, a trade group, to develop standards for event weather preparedness. Known as ES1.7, they were published in 2021 and accredited by the American National Standards Institute, a nonprofit that coordinates voluntary standards. The standards are inconsistently applied, but stress the need for granular weather forecasts and ample advanced planning. 

“The decisions and the triggers for pulling the plug on an event have to be made in advance,” Kloesel says. “If you’re making it at the event, there are too many different interests.”

As an event draws near, Kloesel says mitigating weather risks can butt up against pressure to go on with the show. Artists, promoters and venues have few incentives to cancel or postpone, a decision likely to cost them fans’ favor and money. 

“I have seen some contracts where the promoters are like, ‘If the show doesn’t happen, [the artists] don’t get paid,’” says Justin Goldner, a musician and producer based in New York City. 

Dominic Green, who co-owns Crybaby, an event space in Oakland, California, says established artists often ask for an upfront deposit of at least 50%. “If you’re canceling the day of and acts have flown in, more than likely you’re not getting that money back,” he says. “So you’re losing millions.”

That isn’t to say no one cancels. Last month, the Lovers & Friends festival in Las Vegas was called off less than 12 hours before it was set to begin due to the risk of high winds. But the financial tension is why some say there should be more explicit regulations, including an obligation to cancel when a certain level of heat is expected, or if a storm is too close. “Way too many safety precautions that I’ve seen are left up to a single individual at each venue that does their best and guess what’s going to be safest,” Young says. 

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