Iceman on Everest: 'It Was Easy' Wim Hof stuns observers worldwide with his ability to withstand extreme cold.

March 7, 2008 -- It's a bitterly cold winter day and students on the University of Minnesota campus are bundled up, hurrying to their next class. Wim Hof, dressed in shorts, sandals and nothing else, appeared from the doorway of a school building.

He's known as 'The Ice Man."

Scientists can't really explain it, but the 48-year-old Dutchman is able to withstand, and even thrive, in temperatures that could be fatal to the average person.

From the Arctic Circle to Mount Everest

It's an ability he discovered in himself as a young man 20 years ago.

"I had a stroll like this in the park with somebody and I saw the ice and I thought, what would happen if I go in there. I was really attracted to it. I went in, got rid of my clothes. Thirty seconds I was in," Hof said. "Tremendous good feeling when I came out and since then, I repeated it every day."

It was the moment that Hof knew that his body was different somehow: He was able to withstand fatally freezing temperatures.

Hof began a lifelong quest to see just how far his abilities would take him. In January of 1999 he traveled 100 miles north of the Arctic Circle to run a half-marathon in his bare feet. Three years later, dressed only in a swimsuit, he dove under the ice at the North Pole and earned a Guinness World Record for the longest amount of time swimming under the ice: 80 meters, almost twice the length of an Olympic-sized pool.

When he didn't experience frostbite or hypothermia, the body's usual reactions to extreme cold, his extraordinary ability started to get the attention of doctors who specialize in extreme medicine.

Dr. Ken Kamler, author of "Surviving the Extremes," has treated dozens of people who tried to climb Mount Everest, and instead nearly died from the frigid temperatures. He couldn't believe it when he got word of a Dutchman making the ascent with no protection other than a pair of shorts.

"People are always looking for new firsts on Everest. It's been climbed so many times now, people climb it without oxygen, they … they climb it with all different kinds of handicaps. But no one has come close to climbing Everest in those kinds of conditions," Dr. Kamler said. "It's … it's almost inconceivable."

Hof made the expedition in shorts.

"It was quite easy," Hof said. "I was in a snowstorm before, say, on the fifteen, sixteen thousand feet up 'til eighteen thousand feet."

"I know my body, I know my mind, I know what I can do," Hof said. And he says he can withstand heat as well as cold.

Nearly Naked, Surrounded by Ice

Dr. Kamler met Hof for the first time at the Rubin Museum in New York, where Hof was set to break another Guinness World Record, this time for remaining nearly naked in ice poured up to his neck.

Hof came out of the museum, stripped to his swim trunks and climbed in a 5-foot tall plexiglass container filled with ice. Once he got in, they poured more ice into the container until it reached his chin.

All the while, Dr. Ken Kamler monitored Hof from outside the tank.

Normally, when a person is exposed to freezing temperatures for a prolonged period of time, the body goes into survival mode, as its liquids begin to freeze.

Frostbite sets in, and in order to save the major organs, the body sacrifices blood flow to the extremities, cutting circulation from the fingers, toes, ears and nose to keep the blood flowing to the organs necessary for survival.

If not treated immediately, the damage to these extremities is irreversible. The other danger is hypothermia, an abnormally low body temperature.

At about 90 degrees, body functions start shutting down, and once that starts, you could be dead within minutes.

But Hof stayed in his tomb of ice for one hour and 12 minutes. Then, the ice was poured out of the tank, and Hof emerged, his skin still pink.

"He's not moving, he's not generating heat, he's not dressed for it, and he's immersed in ice water. And water will transmit heat 30 times faster than air. It literally sucks the life right out of you. And yet, despite all those negative factors, Wim Hof was very calm, very comfortable the entire time that he was immersed in that water," Kamler said.

It was a new entry for the Guinness World Records, but really, no one else out there seems able to compete with him. He just keeps breaking his own records.

Response to Cold 'Completely Obliterated'

At the hypothermia lab at the University of Minnesota in Duluth, scientists who've studied the cold for years say they've never seen anything like it.

Dr. Robert Pozos and Dr. Larry Wittmers, director of the lab, hooked up Hof to heart rate and core temperature monitors to evaluate his body's response after being submerged in an extremely cold water tank.

A normal response might include intense pain, cardiovascular stress and mounting hysteria, but with Hof, it's a much different story.

As he went into the tank, Dr. Wittmers explained, "What you're seeing basically is a situation in which the usual response to a shock or a cold was completely obliterated. There was no — none of the usual response you would see. And those responses that you see in most individuals that are exposed to that type of situation are uncontrollable."

From inside the tank, Hof said, "I feel the cold is a noble force, as they always say, and for me, right now, these readings are important but this is what I do every day in the winter, because I like it."

Since there's nothing abnormal about his body, all doctors can tell is that Hof's secret must lie in the wiring of his brain.

"It's very easy to speculate that the same mind control that you use to control your heart when you're scared also can be called upon to control the other organs in the body. And maybe that's how Wim Hof does this," said Kamler. "That's … it's speculation, but it sort of makes sense, and a lot of scientists are working very hard to try to figure this out now."

One answer might lie in an ancient Himalayan meditation called "Tummo," which is thought to generate heat. Hof began practicing the ritual years ago.

"Legends abound of practitioners of Tummo sitting out on the ice naked except for wet sheets that they have draped around them, and as they meditate, the sheets dry and the ice melts around them, even though it's freezing temperature," Kamler said.

The Mystery of Swimmer Lynne Cox

If there's one ice-lover who has baffled scientists as much as Hof, it's American swimmer Lynne Cox.

At 15, Cox swam the English Channel in 14 hours, a Guinness World Record. She has also written two books about her adventures: "Grayson" and "Swimming to Antarctica."

Like Hof, Lynne soon discovered that she had an almost super-human ability to survive in frigid water. In 1987, she became the first person to swim across the Bering Strait, from Alaska to what was then the Soviet Union, in 38-degree water.

And in 2002, she set a new goal: to swim a mile through the massive icebergs of the Antarctic.

Like Hof, Cox prepares herself by somehow using her mind to control her body's temperature.

"I went into the cabin and sat down and focused and breathed and thought about how I was gonna enter the water, how I was gonna do the swim. I sort of … I went through a mental rehearsal of it all. And that preparation, my body knew that I was going to jump into very cold water," Cox said. "Before I went in the water, one of the doctors took my core temperature, my internal temperature, and found it was 102.2."

The water was 32 degrees and hovering near the freezing point.

Without a wet suit or a dry suit, in wind gusting 35 knots, Cox used metal steps to enter the water.

"As I came down, it was like stepping on ice trays," she said.

She began swimming between the icebergs.

"That was amazing to be able to physically do it," she said.

But how do they do it? Kamler said the answer lies deep in the brain. "It's a mystery that we have not yet come close to solving, although we do have tantalizing clues," he said. "It tells us that there's enormous potential within the brain that is going untapped. And if we can study them more, and study people like them more, maybe we can unleash that potential for the rest of us."

Wim Hof's charity foundation, Happy People of the World, is based in the Netherlands. Visit the Web site at http://www.happypeopleoftheworld.com