Temperatures in Death Valley National Park in California have soared to world record highs, causing trouble for a group of motorcyclists traveling through the park.
But temperatures reached a record 128 degrees Saturday, meaning emergency medical helicopters could not be dispatched to the scene because they cannot fly safely in temperatures above 120 degrees, according to the National Park Service.
One rider died from heat exhaustion near Badwater Basin, another was hospitalized in a Las Vegas hospital with severe heatstroke, while the other four were treated in the park and released.
According to Backpacker magazine, between 2007 and 2023, 76 people died from hyperthermia at one of more than 400 locations managed by the National Park Service. Research suggests that extreme heat caused by climate change could make such accidents more common in the future. The planet has been hit by record-breaking heatwaves for more than 12 consecutive months, a startling milestone in climate change.
Amid the effects of global warming and extreme heat, grounding of flights, whether by helicopter or commercial aircraft, is another issue that must be addressed as a matter of life and death.
Why high temperatures make flying difficult
Hot air is less dense than cold air, so there are fewer air molecules creating lift, said David Ryan, assistant professor of safety science at Embry-Riddle Aeronautical University in Prescott. That means planes need longer runways and faster speeds to take off, Ryan said.
“The hotter it is, the longer the takeoff distance, and the heavier it is, the longer the takeoff distance,” he said.
Mr. Ryan said most modern passenger planes are tested to operate in temperatures above 120 degrees Fahrenheit, and in some cases up to 130 degrees Fahrenheit. Most Airbus and Boeing flagship jets can take off safely at temperatures up to about 122 degrees Fahrenheit, while smaller regional jets often have lower standards for safe operation.
But Robert Thomas, an assistant professor in the aeronautical sciences department at Embry-Riddle University in Daytona Beach, noted that there is no set temperature that makes a plane too hot to fly because pilots must take into account a variety of factors, including temperature, altitude and wind, to determine whether the plane will function properly.
Mr Thomas said “rugged” helicopters designed for search-and-rescue missions and fighting wildfires could have designs that help overcome performance problems caused by high heat, for example with bigger engines to carry the extra weight.
“If we had tried to rescue people by helicopter, we might have been able to get there, but the extra weight would have reduced our ability to get back and we might not have been able to actually carry the extra passengers,” he said, adding that physical obstacles such as mountains could make it even more difficult.
Thinner air means fewer air molecules to mix with the plane’s fuel, Thomas said, adding that some planes also have turbine engines or turbochargers that artificially make the air denser.
“When temperatures get that high, it helps, but it’s not a cure-all,” Thomas said.
What happens when a helicopter gets too hot in Death Valley
If a visitor experiences a medical emergency in temperatures above 120 degrees, staff including paramedics will transport them in an ambulance to an altitude of 3,000 feet, where temperatures are typically 5 to 10 degrees cooler, said Death Valley National Park spokeswoman Nicole Andler. The park’s staff can then transport the visitor by helicopter to a nearby hospital, she said.
If a visitor’s location is unknown, the California Highway Patrol and other local authorities may use helicopters to conduct an aerial search of the park’s 3.4 million acres, but they may not be able to land or pick up additional passengers.
Heat has always been an attraction in Death Valley, Andler said, and the park has never been closed due to high temperatures. Climate models predict that extreme weather in the region will become more severe in the future, which could result in an increase in heatstroke in the park, just as it has in the Grand Canyon.
Even a few degrees warmer could make it harder for helicopters to rescue tourists in distress, but Andler said staff were working hard to educate tourists on how to prevent such emergencies in the first place.
“It’s fun and exciting to come here when it’s really hot, and we know that happens and it’s a very real scenario for visitors,” she said, “but we just want to remind people to make those good choices.”
Contributors: Natalie Neisa Alund and Zach Wichter, USA TODAY; Michael Salerno, The Arizona Republic