Antarctica was never inhabited in the past and is not permanently inhabited even in contemporary times by any human population in the strict sense. However, during the year, between 1,000 (winter months) and 4,000 (summer months) people reside in the more than 80 scientific research bases or stations scattered therein.
The only two civilian population centers are Villa Las Estrellas on King George Island and Esperanza at Hope Bay. In midwinter July 2005, 79 women and 162 men resided at McMurdo Base, the largest. The first human being born on this continent is the Argentine Emilio Palma, born in 1978 in the Argentine colony of Esperanza.
In 1986/87 two children were born in the Villa Las Estrellas, in the Chilean station Marsh, now called Frei. Human adaptive behavior to Antarctic conditions: A review of physiological aspects, research published on the WIREs mechanisms of disease, explained: "The Antarctic environment induces adaptive metabolic and neuroendocrine changes associated with survival, as well as increased risks to physical and mental health.
Circadian disruption has been observed in Antarctic expeditioners. The main consequences appear in quality of sleep, which can affect physical and cognitive performance Physiological adaptation to cold is mediated by the norepinephrine and thyroid hormones (T3 and 3,5-T2 metabolite).The observed changes in the hypothalamic-pituitary-thyroid (HPT) axis of expeditioners varied according to temperature, photoperiod, time spent in the cold environment and stress level.
The decrease in T3 levels has frequently been associated with mood swings.Psychological and physical stressors cause disturbances in the hypothalamic-pituitary-adrenal (HPA) axis, with consequent maintenance of high cortisol levels, leading to memory impairment , immunosuppression, and cardiometabolic and reproductive disorders.
Preventive measures, such as pro vision of adequate food, well-established eating times, physical activity and even the use of phototherapy, can all help maintain the circadian rhythm. In addition, the use of high-tech clothing and room temperature control in research stations provide greater protection against the effects of intense cold.
However, psychological stress requires a more individualized approach based on the crew's sociocultural characteristics, but it can be mitigated by mental healthcare and training in coping strategies."