Iceman on Everest: 'It Was Easy'

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.

(Henny Boogert )

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