What Is the Hardest Part of an Expedition?

National Geographic explorers reveal the toughest physical, mental, and emotional challenges they face during expeditions. Explorers interviewed include Clare Fieseler, Mike Shepard, Catherine Workman, Bradley Russell, John Francis, Juan Martinez, Amy Dickman, Aziz Abu Sarah, Enric Sala, and Lee Burger. Now you tell us: What’s the hardest part of your job?

To learn more about National Geographic's explorers, or to find out how to become one yourself, visit
http://www.nationalgeographic.com/explorers/.