Letter: Polar insomnia on the Antarctic continent.
D000222:Adaptation, Physiological; D000864:Antarctic Regions; D003081:Cold Climate; D005101:Expeditions; D006801:Humans; D012621:Seasons; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000209:etiology; D012934:Social Isolation; D013315:Stress, Psychological / Q000150:complications