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