Fred is a physician and family man from South Pasadena, California, where he runs the local Diabetes Care Program. His passion for climbing and mountaineering dates back more than 30 years, and he's completed successful ascents on both rock and ice throughout North America and Asia. He maintains a fine balance between career, family and hobby.

"My quality climbing time has evolved from lots of weekend rock climbing trips and occasional ice climbing sessions into more widely spaced visits to Alaska and the Himalayas," he says. "Now, at this point in my life, it's in many ways easier to go on an expedition than complete a weekly trip to the crags."

Ziel summited Everest from the south side in 2003. It was a long, drawn-out affair, which included an earlier aborted summit attempt due to high winds around the Balcony. When faced with such a stumbling block, many climbers would have lacked the tenacity to try for the summit a second time. And having spent months shuttling equipment up the southern side of the mountain, acclimatizing to the high altitude and suffering from combined wind and snow blindness a few yards from the summit, you might question why Fred would want to return to the mountain again. In 2005, he attempted the North Face, but had to turn back when he developed pneumonia at 27,390 feet (8,300 metres).

For him, however, the choice is simple. "My personal mind-set is that Everest North is an entirely different mountain from Everest South."