He is the third person to have summited Mount Everest in a solo ascent, climbing from South Col to the top on October 24, 1981.
In 2000, Peter Hackett was an emergency physician in Grand Junction, Colorado, and a Professor of Medicine at the University of Washington in Seattle.
In 1982, he and Bill Mills started a rescue clinic and lab on Mount Denali in Alaska, at 4,267 m (14,000 ft) (funded by the US Army and the National Park Service), where again they treated patients with altitude sickness and gathered information.
[3] Hackett has also published on drug use among Everest climbers; his 2016 study, co-authored with Andrew Luks, Colin Grissom, and Luanne Freer and published in High Altitude Medicine & Biology,[4] suggested that the use of performance-enhancing substances, "while present on the mountain, isn't a serious problem".
On the descent he fell through a layer of snow at the Hillary Step, and after a drop of 10–15 ft (3.0–4.6 m) he found himself hanging upside down with his right boot, snagged on some rock, holding him up.