1. Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington. Seattle, Washington, USA.
2. Everest ER, Himalayan Rescue Association, Kathmandu, Nepal.
3. Division of Pulmonary and Critical Care Medicine, Intermountain Medical Center and the University of Utah, Salt Lake City, Utah, USA.
4. Division of Emergency Medicine, University of Utah, Salt Lake City, Utah, USA.
5. Division of Pulmonary and Critical Care Medicine, Sound Physicians, St. Mary's Medical Center, San Francisco, California, USA.
6. Medical Service, VA Puget Sound Health Care System, Seattle, Washington, USA.
7. Altitude Research Center, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.