Extreme Terrestrial Environments: Life in Thermal Stress and Hypoxia. A Narrative Review

Abstract

Living, working and exercising in extreme terrestrial environments are challenging tasks even for healthy humans of the modern new age. The issue is not just survival in remote environments but rather the achievement of optimal performance in everyday life, occupation, and sports. Various adaptive biological processes can take place to cope with the specific stressors of extreme terrestrial environments like cold, heat, and hypoxia (high altitude). This review provides an overview of the physiological and morphological aspects of adaptive responses in these environmental stressors at the level of organs, tissues, and cells. Furthermore, adjustments existing in native people living in such extreme conditions on the earth as well as acute adaptive responses in newcomers are discussed. These insights into general adaptability of humans are complemented by outcomes of specific acclimatization/acclimation studies adding important information how to cope appropriately with extreme environmental temperatures and hypoxia.

Effects of altitude changes on mild‑to‑moderate closed‑head injury in rats following acute high‑altitude exposure

“…Abrupt exposure to higher altitudes (>3,500 m above sea level) can cause acute mountain sickness and can lead to complications, including HACE, high-altitude pulmonary oedema, reduced body heat metabolism in plateau, increased evaporation, and significant dehydration, which in turn lead to increased difficulty in treatment of TBI (24,25). To the best of our knowledge, no previous reports have described the neurological, pathophysiology and imaging characteristics of the acute phase of mmCHI at varying high-altitudes.…”

Accidental hypothermia in recreational activities in the mountains: A narrative review

“…Acute cold exposure results in a series of behavioral and homoeostatic responses to reduce heat flow from the core to the environment and maintain core body temperature . Cutaneous vasoconstriction and thermogenesis are the most important mechanisms.…”

“…Acute cold exposure results in a series of behavioral and homoeostatic responses to reduce heat flow from the core to the environment and maintain core body temperature. 22,23 Cutaneous vasoconstriction and thermogenesis are the most important mechanisms. Peripheral vasoconstriction reduces peripheral blood flow and thus minimizes convective heat flow to the environment when a temperature gradient exists between skin and ambient temperature.…”

Correlation Between Haematocrit Level and the Dural Sinus Density: An Experience of a Single Center in Taif, Saudi Arabia

“…It is well known that hypoxia resulted from chronic high altitude produces an increase in hemoglobin concentration as well as red blood cell count and hematocrit values. [1][2] In addition, recently Akunov et al (2018) concluded that hemoglobin levels have a linear relationship with the duration of exposure to intermittent hypoxia. 3 This increase in the levels of hemoglobin or hematocrite levels result in an increase in x-ray attenuation within the vasculature ,4 which may lead to variability between patients in the radiodensity on CT images within the intracranial vasculature.…”