What Doesn't Kill Us

How Freezing Water, Extreme Altitude, and Environmental Conditioning Will Renew Our Lost Evolutionary Strength

Journalist Scott Carney investigates Wim Hof’s cold exposure and breathing methods. He enters a skeptic but emerges a believer, joining Hof on a record-breaking ascent of Mount Kilimanjaro.

For those unfamiliar, Wim Hof is a Dutch extreme athlete known for his ability to thrive in low temperatures. He ran a half marathon barefoot in ice and snow. He set a Guinness World Record for the farthest swim under ice. In preparing for said record, he swam without goggles and froze his corneas.

Most would agree Hof proves an exceptional specimen. But are his abilities teachable? I appreciated Carney’s skeptical approach and willingness to share contradicting data.

One theory posits Hof’s cold resistance stems from an above average amount of brown adipose tissue. Does Hof’s method promote generation of such tissue? Carney points out Hof’s twin brother exhibits similar levels of brown adipose tissue, yet follows none of the protocols or breathing methods. Yet Carney boosted his own cold tolerance and physical capability by following Hof’s method.

Further, Hof appears to have some control over his parasympathetic nervous system. But Carney admits reliable measurement of such a talent remains outside our scientific means.

Though I remain skeptical, I enjoyed the book’s thesis. The notion that adversity and discomfort can improve our well-being reframes obstacles as opportunities. As someone who hates the cold, this resonated. That said, I’m still not taking cold showers. But I might start.