CAMP FOUR Veteran climber and deputy team leader Ed Viesturs, who has summitted Everest four times without supplemental oxygen, climbs through the Yellow Band, as he heads to the South Col, followed up the sheer face by the Everest film expedition members. Courtesy of National Geographic Society. Except for rocky Hillary Step, the final 3,000 feet is challenging for its altitude, not technical difficulty. The brain works at a third-grade level.
Climbers suffer a loss of appetite and sleep and have constant headaches.