65 years old (Born on April 20, 1959)
Known for his 2011 book Becoming the Iceman (co-written with Justin Rosales), this Dutch daredevil rose to fame for his unique ability to survive sub-zero conditions through what both he and a 2011 scientific study claimed to be mental regulation of his body's internal temperature. He completed a marathon in negative four-degree (Fahrenheit) weather and climbed both Mount Kilimanjaro and Mount Everest wearing nothing but shorts.