An exercise psychologist who's summited Mount Everest says it's important to mentally prepare to make it both up and back down the mountain.
At least 11 people died in Mount Everest's "Death Zone" this past week. At 26,000 feet, the body starts to die, cell by cell, of oxygen deprivation.
How summit fever leads mountain climbers on Mount Everest to make bad decisions, according to social psychologists.
Everest record-holder Lhakpa Sherpa knows what it's like to summit the world's highest peak better than almost anyone else on the planet.