Illustration of runner silhouette heading towards the sun
Illustration of runner silhouette heading towards the sun
Physical exertion on a hot day hits the body’s heat regulation systems twofold, as hardworking muscles warm the body from the inside out while it’s already in overdrive to stay cool. (Illustration: Brian Stauffer)

Philip Kreycik Wasn’t Supposed to Die This Way


He was an environmentalist versed in the dangers of our warming world, an expert trail runner, and eminently capable of moving far and fast outside. The heat killed him all the same.


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A few days after the Fourth of July in 2021, Chris Thoburn swiped open his texts to see two waiting from his friend Philip Kreycik.

“I’ve got a free pass Friday night and Saturday morning if you’re up for a run,” Kreycik wrote. His wife, Jen, had taken their kids, ages ten months and three years, to visit her parents for the night.

Kreycik, 37, and Thoburn, 32, had been friends since Kreycik moved to Berkeley in 2017. They’d met on Strava, when Thoburn spotted Kreycik dropping fast times on some steep trails and reached out about meeting up. Over the years, they’d run all over the Bay Area.

It would be fun, Kreycik’s second text read, to check out somewhere new.

Though their only time together was spent running, the pair had become close, spending long runs talking about their lives. Thoburn, a software engineer, was trying to become a professional ultrarunner. Kreycik had just started a new job at Pacific Gas & Electric, developing the utility giant’s electric- vehicle charging strategy.

“Very interested,” Thoburn shot back. The men settled on a mellow Friday-evening run in the Oakland hills.

Another runner met them there, and when the trio stopped that night at the Redwood Peak summit around sunset, it was still warm out. News reports that week had warned of approaching triple-digit temperatures, the latest in a series of record-breaking heat waves that baked the West all through that summer and had already killed hundreds of people across the Pacific Northwest. That night and in the coming days, nearly all of Northern California was under an excessive-heat warning, but the most dangerous temperatures would be felt only farther east, too far from the ocean to feel its cooling effects.

In Oakland, it was a rare and perfect 80-degree night. Thoburn unzipped his pack and passed each man a beer. They talked about the weekend, and Kreycik’s hopes to run. His drive to meet his family at Jen’s parents’ house in Stockton, 90 minutes east, seemed like a good opportunity to try a new route in the vast network of parks along the way.

Back home that night, Kreycik opened Strava and mapped a nine-mile loop in Pleasanton Ridge Regional Park, a 9,100-acre swath of public land 30 minutes southeast of Berkeley. The run might take a little over an hour. The trailhead, in a neighborhood near the park, was just a mile off the 580 freeway.

Saturday morning, Kreycik talked to Jen on the phone. Make sure to wear sunscreen, she told him, and bring water. She was worried about the heat. “Of course,” he said.

He texted her from the trailhead later that morning: “Eta 12:35ish.” That didn’t give him enough time for the full loop he’d planned, but the route was easy to modify—he’d take a straight shot up to the ridge, then out on the Northridge Trail until he ran out of time. He pulled off his shirt and tucked his phone under the front seat.

He left his water bottle in the center console, locked the Prius, clicked start on his Suunto sports watch, and set off down the narrow dirt track. The trail dipped into the oak and laurel trees, hugging the side of a ravine before turning steeply upward toward the ridge. It was 10:49 A.M. A nearby weather station registered the temperature at 87.

Kreycik pushed hard, his five-foot-11-inch frame all elbows and angles under a sweep of overgrown brown hair. He broke course records on nearly every Strava segment he covered, laying down times most runners would be hard-pressed to beat, even on a cooler day.

Cresting the ridge, the trail opened up into sweeping views of the rolling landscape below: the earth like a wrinkled hide under a stubble of golden grass, with oak-forest oases in every canyon crease.

At the Northridge Trail intersection, the access gate was closed, but the lowest strand of barbed wire strung beside it was usually loose, and many trail users just slipped underneath. Kreycik turned south into the park.

A few minutes later, he took a side trail. Then, 25 minutes into his run, at a T in the trail, he turned around, leaving a single footprint in the dust.

As Kreycik’s 12:35 arrival approached, Jen pulled out her phone to check his location and ETA. Google Maps showed that his phone was still at the trailhead parking lot in Pleasanton. Annoyed and confused, she delayed their meal. By 2 P.M., Jen and her parents had given up waiting, and Jen called Kreycik’s folks to see if they’d heard from him. Wait an hour, Keith and Marcia Kreycik suggested, then try the police. Cops make welfare checks all the time, they said. It’s probably nothing.

Jen hung up. She waited five more minutes, then dialed.

Many endurance athletes and outdoors people have a short but memorable list of close calls: a wrong turn, an equipment failure, a roadside rescue by a stranger. Kreycik was well known for the stories he told about his. There was the time when, in his twenties in Alaska, a young grizzly bear cornered him against a cliff, sniffing out what Kreycik realized only afterward must have been a Nalgene full of berries in his backpack. Or when, while trekking in Kyrgyzstan in 2011, he and a friend narrowly escaped being mugged by a drunken horseman.

Despite the stories—or maybe in part because of them—friends and family saw him as the kind of person who could calmly and capably navigate a mishap. Experienced and exceptionally fit, “he was outstanding at almost everything he ever did,” says Kreycik’s father, Keith. He was a standout cross-country runner at his Richmond, Virginia, high school. In college at Harvard he was a cyclist, rower, and a leader of the Outing Club. He was a curious, joyful adventurer, known for saying yes to nearly anything.

“We met Labor Day of 2011,” Jen recalls, “and he asked me if I wanted to sleep on a pond.” The following spring, as the Boston weather warmed, she finally agreed, and the pair biked the 15 miles to Walden Pond. The park was closed after dark, but they dropped an inflatable raft in the water anyway. “When we woke up in the morning, the fog was lifting, so we were in this in-between layer, this tiny bit of space under the fog,” she says. “It was magical.”

After Kreycik’s children were born, he found creative ways to include them on adventures and runs, becoming an expert at navigating steep trails with a running stroller. His love for the outdoors and living sustainably translated into a career devoted to environmental initiatives, from developing recycling and energy-saving programs at Harvard after he graduated to his most recent work on electric-vehicle infrastructure. And always, he found any excuse he could to seek out wild new places and see just how much his body could do.

This was a man who would pause on a run to text Jen a beautiful photo; who would pick plums from the trees lining Berkeley’s sidewalks and later pull them from his pockets to offer them—grinning—to his running mates. He’d piloted a tandem bicycle with Jen from Cambridge to the Canadian border in a single day just to see if they could, and showed up to group rides on his infamous folding bike, and easily paced with the leaders. He didn’t have a competitive spirit, Thoburn says, “but he had a whole other gear he reserved for when he was on his own. He could eat up trails like nobody else.”

For all those reasons, when Marcia Kreycik hung up the phone with Jen that afternoon, after suggesting she wait to call the police, she assumed her son would be fine. “My first thought was that she was overreacting,” she says. “He’s always OK.”

Kreycik with his wife, Jen, and their two children
Kreycik with his wife, Jen, and their two children (Jen Kreycik)

Thoburn was busy with chores that day when, around 3:30, his phone lit up with a call from Kreycik’s number. It was the police. From there, Thoburn says, the details blur.

Kreycik was missing. Police had found his car at a trailhead parking lot. They’d looked through his phone, text history, and Strava account and wanted to confirm: Had Thoburn and Kreycik run together the night before?

Yes, Thoburn remembers answering, still in shock. And yes, Kreycik planned to run today. Yes, he was happy, had things he was excited about. The officer hung up. Thoburn didn’t even know which department had called.

As soon as the conversation ended, Thoburn says, “my first instinct is, oh shit, I need to go help find him. Then it was just helplessness, because I had no idea where to start.” Kreycik hadn’t told him where he planned to go and the cops hadn’t either.

Thoburn didn’t have Jen’s number. He tried email, then Facebook. He texted other runners about helping search; considered just picking a park they’d talked about the night before. Anything to start looking.

Around 6 P.M., Jen sent a map of the trailhead. Thoburn threw gear and water into his trunk. When he got to Pleasanton, county search-and-rescue teams from across the region were already there, and Thoburn filled them in on everything he knew, what Kreycik might do, and how he might have shortened the route—which the police had gleaned from his Strava account—to fit his timeframe.

Thoburn asked the SAR team if he could help search. Since he wasn’t part of a SAR unit, they couldn’t officially ask him to, he remembers being told. But they wouldn’t stop him, either.

As the summer sky darkened, the temperature still 85 degrees, Thoburn and a friend ran the southern end of Kreycik’s planned route, calling his name and scouring the trail with their flashlights. Three hours later, they briefly returned to the trailhead, and then Thoburn went out again, this time with a park neighbor who knew of some unmapped singletrack. It was after 2 A.M. when he got home.

On just a few hours’ sleep, Thoburn drove back to the park the next day, armed with maps and more ideas about where his friend might have gone. While up on the ridge, he got a call from Tom Wooten, a close friend from Kreycik’s days at Harvard.

Wooten had seen a family Strava post and at first had assumed it was a joke—he couldn’t imagine his old friend ever getting lost, or if he did, not having the smarts or endurance to make it out. But a call to Kreycik’s dad confirmed the worst. Stuck on the East Coast but hoping to help get lots of people into the hills fast, he called Thoburn.

“Is it OK if I put your contact info out there?” Wooten asked. He shot off emails to Harvard friends living in the Bay Area and made a Facebook post; word of the search quickly went viral. A Pleasanton community leader, Sandy Schneider, saw a post and shared it to every outdoor group she could find on Facebook.

News reports that week had warned of approaching triple-digit temperatures, the latest in a series of record-breaking heat waves that baked the West all through that summer and had killed hundreds of people across the Pacific Northwest.

By Sunday afternoon, Thoburn recalls, “the phone calls just started rolling in and rolling in and rolling in.” Monday morning, some 60 volunteers stood in the parking lot, waiting to help. Tuesday, there were more.

Among them were Betsy Everett and Carlo Facchino, runners and roommates who coordinate a series of Bay Area endurance events.

“It really hit home that this could be me,” Facchino says. “I don’t run with my phone. Ninety percent of the time I forget my GPS watch. I probably would have forgotten my water bottle.” So would most people he knew.

They joined more than 2,000 volunteers working with Thoburn to augment the official SAR search. Everett came almost every day, others came when they could, still more contributed from afar, managing a Facebook group and collecting searchers’ tracks on Strava. Some were Kreycik’s coworkers, family, and friends who flew in to help. Some were outdoors people eager to use their skills. Others lived close to the park.

More than a dozen SAR agencies searched too, responding to the call with teams, drones, and dogs. Local officials called it one of the biggest searches in state history.

“Everywhere you looked, it seemed, people were going through the trees, and going off the trails, clearing all the areas,” Facchino says, recalling his first day there. “I think everybody had a confidence that he was going to be found.”

But three days passed, with no sign of Kreycik.

July 13, a park neighbor reported hearing cries for help in a canyon near his route, but an extensive overnight search found nothing. Later that week, the official SAR effort scaled back because of a lack of clues, leaving only Thoburn’s cadre of community volunteers, who kept coming back even as hope waned.

Near the end of the month, Sergeant Ray Kelly of the Alameda County Sheriff’s office told local reporters: “We’re mystified, we’re frustrated, we’re perplexed as to why we haven’t found Philip.” It was possible, his office speculated, that Kreycik wasn’t there at all.

Theories swirled on Facebook posts and subreddits. Some guessed that Kreycik had left the park altogether, or that a mountain lion had killed him. Facchino and Everett heard rumors of landowners on the isolated edges of the park pulling rifles on searchers and wondered if Kreycik had been shot.

Thoburn had a different theory. “My assumption from the first moment was that this was a heat-related event,” he says. Kreycik would have pushed hard on the hills, he figured, despite the weather. “That was just his style.”

A lifelong endurance athlete used to training at the limit, Thoburn had experienced some of the symptoms of heat illness himself: dizziness, confusion, unusual decision-making, even hallucinations. Between dehydration and heat stress, he says, “it is a rare trail runner that does not have a story.”

Among all natural hazards, heat is one of the deadliest. According to the Environmental Protection Agency, heat is the “leading weather-related killer in the United States.” Government data derived from death-record information suggests that at least 700 people die of heat-related illnesses each year, but recent investigations by the New York Times and Los Angeles Times have shown that the real number could be as much as six times higher. A 2020 study published in the journal Environmental Epidemiology suggests that in 297 counties in the U.S., about 5,600 people die each year from heat.

Athletes are among those most at risk of heat stroke, and research involving marathoners has shown that the fitter you are, the more danger you face. The harder runners push, the more their bodies overheat. And in highly trained athletes and soldiers, the symptoms of going over the line usually aren’t obvious. “You compensate pretty well until you crash,” says Caleb Dresser, a Harvard instructor, emergency physician, and expert on heat and climate disasters.

Physical exertion on a hot day hits the body’s heat regulation systems twofold, as hardworking muscles warm the body from the inside out while it’s already in overdrive to stay cool.

One of the first symptoms is usually the light-headedness of heat exhaustion. From there, as the body burns through fluids and its ability to compensate is thrown off, internal temperatures can rise above 104 degrees, the threshold for heat stroke, in ten to 15 minutes. Unless a person stops exercising and gets out of the heat, the symptoms cascade into confusion, delirium, convulsive seizures, and coma as organs begin to fail.

By that point, says Dresser, unless there are “immediate and maximally aggressive medical interventions” in an emergency room, most cases are fatal. Those include external measures like ice-water immersion and cooling with fans and mists, or internal measures such as intravenous fluids. In extreme situations, patients are chemically paralyzed, put on a ventilator, and intravenously pumped with cool saline. “It’s a situation where minutes matter,” Dresser says. “Once you are above 104 degrees, you start getting into the territory where the cells of the body are being permanently damaged.”

As climate change pushes global temperatures higher, climatologists and physicians agree that heat waves will only become more frequent and deadlier. During the record-breaking heat of 2021, SAR agencies in Washington State were stretched thin, despite smart decisions to bring in backup ahead of heat waves. In California, at least six hikers died from heat-related injuries, including three people in Death Valley and an entire family hiking near Yosemite. Jonathan Gerrish, Ellen Chung, their baby, and the family dog were all found dead on the trail on a day that hit 109 degrees. An unsent text message later recovered by authorities read, “No water or ver [over] heating with baby.”

A body of international research and SAR organization reports show that events like these, along with less predictable storms, longer warm seasons, and increasing rockslides associated with melting ice, have already resulted in more—and more dangerous—searches as outdoors people get caught in conditions they weren’t prepared for, because the world they’d always adventured in has changed.

Chris Thoburn, far left, and Philip Kreycik, rear right, pause for a photo with friends before a group run at Las Trampas Regional Park in the East Bay.
Chris Thoburn, far left, and Philip Kreycik, rear right, pause for a photo with friends before a group run at Las Trampas Regional Park in the East Bay. (Chris Thoburn)

On August 3, Facchino and Thoburn met at the parking lot where Kreycik began his run. They’d been searching for 25 days. By then, only the hardiest searchers remained.

Several tips had come in over the previous days: a drone pilot had spotted a body-shaped shadow; searchers at two other sites had reported pungent smells, a signature sign of decay.

From the parking lot, Thoburn, Facchino, and a third man set out on foot to check each area. The first site, one of the reported smells, yielded nothing. Neither did their investigation of the drone’s report. The men continued, hiking north down a side spur of the Northridge Trail. Below them, the city of Pleasanton gleamed; the highway and BART trains rumbled.

Shin-deep in dried grass just off the trail, they reached the final coordinates of the day. The reported smell was still there. It was strong.

Thoburn and Facchino worked their way down the hillside, trying to track it. Crossing the narrow line of an unmapped trail, they lost the scent, so Facchino turned back until he’d found it again. He looked at the grass, trying to read the wind, then started back downhill.

Near the edge of the trail, under the branches of a large, low oak, he saw a shadow. Then a flash of blue fabric. A shoe. Dread and adrenaline emptied him of words.

“Chris, Chris,” he finally shouted. “I think this is it.”

For weeks Thoburn returned to that thin, unmapped trail, trying to make sense of what happened to his friend. As soon as early autopsy reports ruled out foul play, police confirmed Thoburn’s theory that Kreycik had likely died from heat exposure. Over and over, he ran and hiked the route, going over heat-stroke research and the GPS tracks police had recovered from his friend’s watch.

As Kreycik had run back up the ridge, he’d shortcut below the main trail, straight toward the access gate he’d used coming in. Reaching it, 32 minutes into his run, he paused at a sign on the gate that he likely hadn’t seen on his way in. It said: Area Closed, No Entry.

“I think he decided that this wasn’t his gate,” Thoburn says, staring at that sign on a warm September day, hiking his friend’s route one more time. Confused and dehydrated, Thoburn says, “it would have been easy for him to think, Oh, I must have passed this the first time. That there’s another gate, and he needs to keep going.”

Kreycik kept going. Just seconds up the trail, he veered onto the Northridge spur, up and over a hillcrest with wide views of the city. Then the trail dropped, steeply, to another gate, and another No Entry sign. But by now, Thoburn thinks, even if Kreycik had been thinking clearly, even if he’d known he was off-track, “this is the point at which you realize you can’t go back.” The hill back up is too steep; the neighborhoods below too promising.

“It really hit home that this could be me,” Carlo Facchino says. “I don’t run with my phone. Ninety percent of the time I forget my GPS watch. I probably would have forgotten my water bottle.” So would most people he knew.

Kreycik hopped or crawled under the gate and kept going. Then, 39 minutes into the run, Kreycik left the trail. Thoburn can’t explain it; it doesn’t make sense. Steering away from the trail, away from the city, he ran toward a single, large tree down the hillside. Reaching it, he ran into the forest beyond, which fell steeply into a leaf-strewn ravine.

Down the treacherous hillside, Kreycik kept going to a fire road, reaching a sharp switchback where a narrow trail extended into the woods. He took it. He’d been running for more than 45 minutes. Weather stations around the park logged the temperature at 93 degrees and rising.

Deep in the forest, he stopped, recovering, for 50 more minutes, almost certainly unaware that a few hundred yards farther on there was a ranger house and a water tank, just out of sight. For those 50 minutes, his GPS pin drifted around a single location. “If you look right here,” Thoburn says, pointing at the ground, “there’s an interesting depression. You just, you fit right into it,” he says, sitting. “I do wonder if this was literally the spot” where he rested.

“And then after that hour, he goes straight back up the hill,” Thoburn says, describing what he believes was a final, last-ditch effort: moving in a straight line toward his car. Whether Kreycik knew, whether he’d found the map function on his watch and drawn a line or just followed a fence across the sweltering hillside, is impossible to know. But the route took him steeply up, straight into the hundred-degree sun for 20 minutes, before he stopped at another steep ravine and turned around, retracing his steps. Near the edge of a grassy clearing, near the thin line of the trail, he stopped again.

Kreycik’s watch recorded no biometric data. But starting at 2:34 P.M., at the edge of that clearing, it registered rapid movement where there should have been none, for almost an hour. The full coroner’s report has not been released, but the movements, the coroner’s office said, were consistent with seizures. The weather station nearby registered its peak of 101 degrees.

Around 3:20 P.M., in that quiet grove beneath the shadow of an oak, Kreycik’s watch stopped. Thoburn thinks it must have been inadvertent, the button getting contact during convulsions. Authorities do not believe Kreycik lived much beyond it; he was gone before anyone started looking.