For hikers in the American Southwest, this searing hot summer has been an exceptionally dangerous one.
A teenager collapsed at Big Bend National Park in Texas in late June, while his stepfather crashed a car as he sought help. Both died. A woman never finished her trek along a remote trail last month in the Grand Canyon in Arizona. And two people visiting Death Valley in California perished during some of hottest temperatures ever recorded on Earth.
Altogether, national and state parks have reported at least seven possible heat-related deaths so far this summer, as a brutal heat wave has baked the Southwest. Data on hiking fatalities is spotty, and officials caution that causes for the recent deaths have not been confirmed. But the deaths would appear to be the most for the months of June and July in at least a decade.
The losses provide a glimpse of how climate change is reshaping the environment within some of America’s most popular parks, and of the risks that hikers encounter among iconic sights on increasingly hot and dry trails.
“We’re seeing this enormous spike of these really tragic events right now,” said Dr. Grant Lipman, a former professor of emergency medicine at Stanford University School of Medicine who founded GOES Health, an app for people seeking medical information in the wilderness.
In Death Valley National Park, which straddles California and Nevada, the hottest spots are inhospitable to even the hardiest cactuses. Two men died there in searing conditions last month as temperatures approached 130 degrees Fahrenheit, the hottest temperature ever reliably recorded anywhere on the planet.
A driver, 65, drifted off the road and was found in his car amid Death Valley’s sun-baked rocks on July 3, the day after a high of 126 degrees. His car did not appear to have working air-conditioning. The other fatality was Steve Curry, 71, a Los Angeles resident who had been hiking in the park and spoke to journalists just hours before he died on July 18, when temperatures reached 121 degrees.
An experienced hiker, Mr. Curry had been resting at an overlook called Zabriskie Point in the shadow of a metal sign, the only sliver of shade he could find. A reporter and a photographer from The Los Angeles Times offered him a ride, which he declined. “Why do I do it?” he said, in response to their questions about hiking in the heat. “Why not?”
Park data shows that despite the apparent spike in fatalities this year, heat-related deaths remain relatively rare. They are vastly outnumbered by fatal car crashes, falls and drownings. Data from 2014 to 2016 shows that, on average, about 330 people died in national parks each year, or roughly six people every week, out of more than 300 million annual visitors.
Preliminary data from the last decade suggests that, on average, about four people have died of heat-related causes each year in national parks.
Parks regularly close trails for risks such as construction, flooding and wildfires. But for the most part, they aim to preserve public access — even to the most forbidding natural landscapes, which are often the most spectacular.
“We don’t want to shut down those opportunities for visitors who are skilled and can manage the environment,” said Jennifer Proctor, who is in charge of public risk management at the National Park Service.
In Death Valley, people can easily enter the park without encountering an employee, and cellphone service is spotty. Rangers have adopted an approach that focuses less on controlling visitors and more on encouraging preparation and caution, typically through online resources and road signs.
Even for veteran employees, though, the conditions can be daunting. “It gets harder for me every year,” said Abby Wines, a park ranger who has worked at Death Valley for 18 years. About 100,000 people visit the park each month during July and August.
The dry heat of the desert can be deceiving, said Rick Gupman, a ranger and the acting superintendent of Big Bend National Park, where the teenager and his stepfather died in June — and where, three weeks earlier, a 22-year-old man who had been hiking in the heat was airlifted to a hospital. He also died.
Temperatures at Big Bend, near Texas’ border with Mexico, can change drastically depending on the elevation or the time of day, Mr. Gupman said, adding, “It creeps up you.”
In Grand Canyon National Park in Arizona, a 57-year-old woman lost consciousness on a hiking trail in early July and died. Two heat-related deaths also occurred on a Nevada trail last month: Rangers said two women, 29 and 34, had been hiking in Valley of Fire State Park but never made it back to their cars.
“Anyone who’s hot and is confused, or has an altered level of consciousness — that’s heatstroke, and that’s a medical emergency,” Dr. Lipman said. “And they need to be cooled down as quickly as possible.”
Keeping visitors safe in a changing climate is complicated, said Ms. Wines, the Death Valley ranger. In many places, including Death Valley, the weather is expected to grow not only hotter but also wetter. That will mean more flash flooding. In August 2022, heavy rain closed every road out of Death Valley, stranding hundreds of visitors for several hours.
The park plans to invest in more resilient roads and more reliable air-conditioning at the visitor’s center, and in improved methods to keep visitors as well-informed as possible — even though preparation remains largely up to them.
“People can have a safe visit here,” Ms. Wines said. “We’re going to give them information about how to do that, rather than tell them what they can and cannot do.”