1. Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy.
2. Department of Emergency Medicine, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
3. Institute of Emergency Care Medicine, University Hospital, Zurich, Switzerland.
4. Department of Medicine, Altitude Research Center, Division of Pulmonary and Critical Care Medicine, University of Colorado, Aurora, Colorado.
5. Department of Internal Medicine, University Hospital, Heidelberg, Germany.
6. VA Puget Sound Health Care System, Pulmonary and Critical Care Medicine, University of Washington, Seattle, Washington.
7. Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, Washington.
8. Department of Emergency Medicine, Stanford University Medical Center, Stanford, California.