But it was on a recent ski-trekking trip in the White Mountains of New Hampshire that he and a group of his students faced life-threatening peril. “We came very close to not making it out at all,” says Mazur.

Eric Mazur has climbed Mount Kilimanjaro, skied down Mont Blanc, gone back-country skiing in the Rockies. Besides being a dean of applied physics at Harvard, Mazur knows his way around maps, compasses, and GPS coordinates.

A combination of near-zero temperatures, bad luck, and regrettable decisions in a massive wilderness area with no cellphone reception turned an overnight outing into a near-disaster. The story of the weekend in the woods is a lesson on how quickly events can take an ominous turn — and how grit ultimately got the group out of a frozen labyrinth.


All six suffered hypothermia and dehydration. Three had severe frostbite that turned gangrous. One was hallucinating. By the time they got to the emergency room at Speare Memorial Hospital in Plymouth, N.H., their body temperatures hovered near 92 degrees. At 90 degrees, Mazur says, the brain doesn’t get adequate oxygen “and that’s the end.”

Mazur has been unable to wear shoes on his frostbitten toes since the February misadventure. He wears open-toed post-op shoes, and three toes on his right foot remain at risk.

A veteran hiker and skier, Mazur has taken students to the backcountry of the White Mountains National Forest without incident most years since 1998. On a recent day, he settled into his Harvard office to talk about this trip. He’s 59, a stocky man dressed in professorial khakis and sweater. Mazur, who lives in Concord, lectures internationally and has been on tour with his new textbook, “Principles & Practice of Physics.”

This week, he was named the first-ever winner of the Minerva Prize, an award given to one professor worldwide for “extraordinary innovation” in teaching. The prize comes with $500,000 in cash.


Besides teaching, Mazur is also passionate about mountains. “I grew up in a flat country, and I live for the mountains,” he says, his voice carrying a hint of the Netherlands. “There’s something magical about mountains.”

It was Feb. 15 and perhaps a bad omen when the five other hikers — four PhD students in their late 20s and professor James Fraser, Mazur’s friend from Queens University in Canada — arrived late to New Hampshire, where Mazur was anxiously waiting. In the hiking world, early starts are a given.

They left Fraser’s car in a parking lot off the Kancamagus Highway not far from Loon Mountain in case they decided to take a southern route out the next day — a route Mazur had done only once, the first time he led a group.

This is where Mazur typically would have questioned rangers about the southern trails: Which are broken in for skis? Which bridges are out? But because they were running late, and he thought Fraser had already asked, Mazur did not speak with the ranger, which he would later regret.

They then drove north to the departure point, a parking lot on Route 302, a few miles from Bretton Woods. It was noon when they donned cross-country skis and shouldered backpacks containing food, water, clothes, and sleeping bags that weighed about 30 pounds each. They had reserved bunks for the night at the Zealand Falls hut, run by the Appalachian Mountain Club.


Mazur relaxed. The paths were clear, the sun out, the fir and birch glades beautiful, the views spectacular. There was a lot of uphill trekking to the hut, which is at 2,600 feet, but they made it by late afternoon. For dinner, they ate the minestrone soup and pasta they’d packed.

Zealand Falls, one of only three White Mountains huts open in the winter, was at capacity with 36 bunks.

The next morning, they decided to explore the southern trail that would ultimately lead to Fraser’s car. If conditions were too difficult, they could always turn around.

But they didn’t set a point of no return and found themselves bogged down on an unbroken trail in deep snow. Single file, they took turns in the lead positions to break in the trail, but made slow progress. The hut ranger had assured them their hiking plans were solid, crossing the Pemigewasset Wilderness toward Loon Mountain.

“He made it appear like it was a walk in the woods,” says Mazur. That’s pretty much what Mazur thought, too: “The White Mountains don’t look like Everest or K2. I’ve always considered them a little bigger than hills.”

“The White Mountains don’t look like Everest or K2. I’ve always considered them a little bigger than hills,” said Eric Mazur, describing his confidence in his group’s plan to cross the Presidential Range. Kayana Szymczak for The Boston Globe/Globe Freelance

It was 15 miles from the hut to the parking lot near Loon, a full day’s hike under the best of circumstances. But this was February of a record-breaking winter. Many of the blue trail markers on the trees were covered with snow.

And there were many fallen trees, with all six having to take off their skis whenever they had to climb over. Each tree meant a 10-minute delay and “there were dozens and dozens and dozens of trees,” Mazur says.


Then there were the creek crossings: “down six feet and up six feet,” each one a 20-minute affair. “Meanwhile, the clock was ticking,” says Mazur.

Their water containers froze solid. They each had only an energy bar to eat. The trail, when they could find it, had become nearly impassable, unbroken and littered with obstacles.

As the sun set, Mazur still wasn’t too concerned; he’d summited Kilimanjaro using a headlamp. At about 6 p.m., now wearing their headlamps, the group reached Stillwater Junction, where several branches of the Pemigewasset River merge. Once across the frozen river, according to Mazur’s GPS, they would hit tracks.

Instead, they were greeted by more fallen trees and huge boulders. Mazur’s ski binding malfunctioned, so he took off his skis and carried them. His feet were freezing and wet. The temperature, he believes, was close to zero.

They were lost in a wilderness with no shelter and no way to communicate with the outside world. “We could see the planes out of Logan fly overhead,” says Mazur. “Ironically, my wife and daughter were flying overhead to Europe that very night.”

Mazur, a glass-half-full guy, kept thinking of a story he had recently read about a Long Island lobsterman who survived a night and a day bobbing in the cold Atlantic without a life preserver after falling overboard 40 miles offshore. He faced sharks, swells, dehydration, hypothermia, and exhaustion, but ultimately was rescued.


If that guy could hang on, literally, then so could Mazur and his group. At least, that’s what he told himself. “That story came back to me all the time,” he says. “It motivated me to say, ‘We’ve got to get out of here.’ ”

At 7 p.m., they were still 10 miles away from the southern parking lot. They were hungry, thirsty, and exhausted. “At that point, the group started to disintegrate,” Mazur says.

Two people wanted to return north to the Zealand Falls hut. But that was a 12-hour hike back. Two wanted to build an igloo-type shelter, but they had no tools, and it would take hours. Mazur and Kelly Miller, a graduate student from Toronto and the only woman in the group, agreed: They had to keep moving south.

They soon found blaze marks on the trees and got on a trail. Mazur’s right foot was freezing, his boot frozen to his sock. He extricated his foot, put on a new sock and toe-warmers, but his frozen sock had to be cut out of the boot by Ben Franta, a student from Iowa, who also dug out the ice lodged in the ski binding. Mazur could now clip back into his ski.

“It was the nicest click I have ever heard in my life,” he says.

At 1:30 a.m., they got to a creek that wasn’t frozen over and was dotted with tree trunks. Fraser led, then Mazur, followed by the others. It would take an hour for all to cross. Shivering on the other side, Mazur told Fraser that he could not stay still, he had to keep moving and would call for help as soon as he got cell reception. Fraser would wait for the others. Each person had a GPS.

The trail descended and Mazur’s skis picked up speed as his headlamp weakened. “Here I am with 30 pounds on my back on an icy trail in the dark, and I don’t know what’s ahead,” he says. “If you fall, it’s hard to get up.”

When his GPS died, he dug out the spare battery, but because of the cold, it would not turn on. By this time, Mazur and the others had been in constant motion for nearly 20 hours, with little water or food.

At 3 a.m., he reached a closed campground, where a map was posted. He still had 2.5 miles to go, but at least he was on the right trail.

Mazur says he never worried that they might not make it out. “But what I didn’t realize was the danger of hypothermia.”

It was 4:30 a.m. on Monday, Feb. 17, when he reached the parking lot. His elation was tempered by the fact that Fraser’s car was locked. But there was a restroom that was unlocked. Inside, he turned on his cell: one bar of power left.

He called 911, but the calls failed. He placed the phone high up in the windowsill on speaker mode and got a call through. A paramedic arrived 15 minutes later, then an ambulance, and finally the State Police, who lectured and questioned him.

At 5:30, just as the troopers were unloading their snowmobiles to look for the others, the group straggled out from the woods. The three who had frostbite — Mazur, Miller, and Franta — were put in the ambulance; the others drove to Speare Memorial. All were treated for severe dehydration and hypothermia, but only the frostbitten were hospitalized.

By the time they got to the emergency room at Speare Memorial Hospital in Plymouth, N.H., their body temperatures hovered near 92 degrees. At 90 degrees, Mazur says, the brain doesn’t get adequate oxygen “and that’s the end.” Eric Mazur

They had logged 17 miles that day, compared to 7 on the first uneventful day.

In the emergency room, a doctor took his index finger and drew a line across the base of Mazur’s toes on both feet. “You’re going to lose all of these,” he said.

“I didn’t believe him, and I was right,” says Mazur, though three of his toes still have gangrous tissue, dead nerves, and no nails.

The students have long since recovered and recently met in their physics lab with Mazur to talk about the trip. Toward the end, Miller had started to hallucinate, a symptom of hypothermia.

“I started seeing and hearing things that weren’t there,” she says. “The trees looked like a village, and there were houses everywhere.” Miller, who had hiked with Mazur’s group last year, says she’d do the one-night version again: “I still think it was fun, except for the last part.”

Alex Raymond, who is from Kansas City, calls the trip “a bonding experience” and says he’d go again.

Franta would, too, but was fearful that they wouldn’t get out. “I thought we were in a very vulnerable position. We lacked the right equipment, and we didn’t have enough clothes and drinkable water. We were equipped for a much shorter hike.”

But the fourth student, who asked not to be identified because his parents don’t know about the ordeal, says no way. “I will never do anything extreme of any kind again,” he says. “Not even close. Not happening again.”

Mazur, of course, will go again: “Why not?”

But he would set a point of no return and learn more about trail conditions. “And probably take another trail.”

Bella English can be reached at english@globe.com.

■ Correction: Because of incorrect information provided to the Globe and a reporting error, an earlier version of this story incorrectly stated the path of a New Hampshire ski trek led by a Harvard professor and the number of Appalachian Mountain Club huts open in the White Mountains in winter. Professor Eric Mazur’s group stayed in the Zealand Falls hut, one of three huts the mountain club has open in that area in winter, and the group made its way through the Pemigewasset Wilderness.