Dr. Clayton T. Cowl is the Chair of the Division of Preventive, Occupational and Aerospace Medicine at Mayo Clinic in Rochester, Minnesota with a joint appointment in the Division of Pulmonary & Critical Care Medicine. Dr. Cowl has ongoing projects focused on respiratory physiology at altitude and environmental aspects of pulmonary disease. He has also conducted research in other areas of transportation medicine, such as safety issues in the commercial driving industry. Dr. Cowl is currently the Immediate Past-President of CHEST (American College of Chest Physicians) and is on the editorial boards of several medical journals.