What we can learn from the death of the family hiking near Yosemite, and too many others

The sprawling investigation looked at possibilities ranging from foul play to lightning strikes to mine gas to toxic algae. But in the end, the deaths of Jonathan Gerrish, 45, Ellen Chung, 30, their 1-year-old daughter Miju and their dog Oski were all attributed to hyperthermia and “probable” dehydration.

It’s rare for multiple hikers to succumb to heatstroke at the same time, according to search and rescue professionals, but during this unprecedentedly blistering summer, hikers fell ill from the heat and died across the state. As climate change ramps up, it’s only going to get worse, experts say, meaning that Californians need to learn how to protect themselves and their families.

Already, too many of us are venturing out in extreme heat without understanding the risks or bringing enough water.  

Although heat-related deaths can be difficult to determine conclusively and are not tracked in California, at least nine people collapsed and died while hiking in extreme temperatures in California this summer. The tally includes three people in Death Valley National Park, one in Anza-Borrego Desert State Park, one on the Pacific Crest Trail in Southern California and one in Pleasanton Ridge Regional Park in the Bay Area.

That last one was of course Philip Kreycik, 37, an ultramarathoner out for a trail run when the temperature rose to 106 degrees. The massive search effort for Kreycik went on for nearly a month and involved hundreds of volunteers and numerous local and state agencies and rescue crews.

Ultimately, GPS data from Kreycik’s smartwatch indicated that he became disoriented and died about five hours into his run. The likely cause was heat exhaustion.

It’s not just hikers who are overheating in California and dying. A recent Los Angeles Times investigation found that between 2010 and 2019, 599 death certificates in California listed heat exposure as the cause. In looking more closely at temperatures and mortality data, though, the LA Times analysis found that heat likely factored into about 3,900 deaths.

Depending on how much humans manage to mitigate climate change, the number of 95-degree days in some areas of California is expected to double, triple or even quadruple by 2050. So what does that mean for those of us still hoping to hike during the warmer months?  

SFGATE talked to search and rescue leaders to understand what California is up against, and how outdoors enthusiasts can protect themselves from heat exhaustion.

For Wes Riggins, president and training director of California Explorer Search and Rescue, it comes down to preparation. In the summertime, Riggins and his team spend a lot of time in Yosemite National Park doing what’s called preventative search and rescue, or PSAR, because “the best op is the one that never happens,” Riggins says.

What the team often finds is that people are not aware of the risks posed by extreme heat. They don’t have enough water. They’ve planned hikes that are too ambitious for the conditions. They’re dressed inappropriately. “If you roll all those things together, it’s a recipe for what we call environmental injuries,” Riggins says.

Hikers with a lot of experience in the outdoors can also run into problems when they fail to recognize risks, as SFGATE recently reported.   

For anyone out on the trails, the importance of carrying enough water cannot be overstated. A half-liter of water per person per hour is standard while hiking, but if the hike is strenuous and the temperature is high, each person needs a full liter per hour.

The reason people need this water is to replace what they lose through sweat, which is the body’s way of cooling itself down. Hydration is crucial for the functioning of all organs, playing an important role in blood flow and kidney function, says Brigham Willis, senior associate dean of medical education at the UC Riverside School of Medicine. “Temperature thresholds vary from person to person, but once it becomes around 105 degrees or more, health consequences become more widespread,” Willis said in an interview for the university.

Unfortunately, one of the first signs that a person may be suffering from heat exhaustion is confusion, according to Riggins, which can exacerbate the problem. In Kreycik’s case, the GPS data indicates that he began zig-zagging toward the end of his run, a possible sign of delirium from heat exhaustion.

Other early signs include headaches, dizziness and clammy skin, Riggins says. “Your heart rate will go up and you could feel nauseous,” he says. “Those are the handful of primary indicators that you’re approaching the pay-attention-to-this zone, if you will.”

It’s especially important when hiking in a group to recognize that there’s a wide tolerance for heat amongst individuals, he continues, meaning that one person might have a problem long before anyone else. It’s rare for two people to fall ill with heat exhaustion simultaneously, Riggins says, but it does happen.

The most obvious and recent example is Gerrish, Chung and their baby, but there have been other reports of pairs of hikers in California who have fallen ill or died because of the heat.

In mid-June, a woman collapsed and died in 100-degree heat on a stretch of the Pacific Crest Trail in Southern California. The heat also impacted her hiking companion, who was taken to the hospital. Just a few days later, during a volunteer count of bighorn sheep in Anza Borrego, extreme desert heat left one hiker dead and another in critical condition.

Deserts are known for being hot and lacking water, and people die from heat exhaustion in places like Death Valley and Joshua Tree National Park nearly every year. But other California landscapes that were once shaded and lush — with available water — have started to change, according to former Yosemite search and rescue employee Jason Torlano.

“I noticed on my last trip in the Clark Range that it was super hard to find water, like never before,” Torlano told SFGATE. “It’s getting harder to find water in the mountains while hiking because of the droughts and less snow staying year-round and springs drying up.”

The other problem, Torlano says, is an increase in the number of burn scars from all the recent wildfires. “Trails through these areas are completely exposed and lack shade or shelter from the intense summer sun,” he says.

The takeaways from environmental changes and high-profile deaths this year are pretty straight-forward: If you’re going to hike in the heat, understand the risks and prepare accordingly.