Chilly Weather and Human Health: Physiology, Adaptation, and Risks The impact of low temperatures on the body represents a complex physiological stress that can carry both potential health benefits and serious threats. The science of the effects of cold — cryomedicine and ecological physiology — studies the mechanisms of adaptation and pathological reactions underlying these opposite effects. Physiological Reactions to Cold: From Thermoregulation to Metabolic Changes When exposed to cold, the body triggers a cascade of compensatory reactions aimed at preserving heat and maintaining the core body temperature (~36-37°C): Peripheral vasoconstriction. Blood vessels in the skin constrict, reducing heat loss and directing blood to vital organs. This leads to pale skin and cooling of the extremities. Cold shivering. Involuntary contractions of skeletal muscles, the main task of which is to generate heat by a sudden increase in energy expenditure. During shivering, heat production can increase by 4-5 times. Non-shivering thermogenesis. A more complex mechanism associated with the activation of brown adipose tissue (BAT). In adults, it is located in the neck area, along the spine, and clavicles. When cooled, the sympathetic nervous system stimulates brown fat to burn lipids and release heat, bypassing the stage of ATP synthesis (oxidative phosphorylation). This is a highly efficient method of thermogenesis. Endocrine changes. Thyroid hormone and catecholamine secretion (adrenaline, noradrenaline) increase, which increases the basal metabolic rate and mobilizes energy resources. Interesting fact: Northern peoples (Saami, Eskimos) have genetic adaptations to cold. They generally have a higher basal metabolic rate, effective vasoconstrictive control, and specific polymorphisms of genes related to fat metabolism and the function of brown adipose tissue. Potential Positive Effects of Controlled Cold Exposure With a wise, dosed, and gradual approach, cold can have a health-promoti ... Read more