1. Centre for Altitude, Space and Extreme Enviroment Medicine, Institute for Human Health and Performance, University College London, London, UK.
2. Vrije University Medical Centre, Amsterdam, Netherlands.
3. General Practitioner, Penrith, Cumbria, UK.
4. St. John Ambulance WA, Belmont, Western Australia, Australia.
5. General Practitioner, Derriton House, Holsworthy, Devon, UK.
6. Center for Sleep and Respiratory Neurobiology, University of Pennsylvania Schools of Medicine and Nursing, Philadelphia, Pennsylvania., USA.