For residents of all northern countries, a great biological hazard is the cold, which negatively affects all the functions of the body. Fatal outcomes when exposed to the cold are very often associated with alcohol consumption. At the same time, the number of survivors, but those who become disabled due to supercooling, seriously exceeds the number of dead. In the case of progressive hypothermia in the human body, a number of negative reactions occur, leading to a drop in temperature, depletion of physical reserves of the heart, liver, muscles, breathing and heartbeat, reduce the tone of vessels and reduce the blood flow rate. All this leads to stasis of blood, oxygen starvation of tissues due to the excessive connection of oxygen with hemoglobin. Under the influence of cold, frostbite most often occurs, manifested by reactive inflammation and necrosis. The main cause is the cooling of the body surface and the thermoregulation disruption. In the course of the emerging necrosis, the role of tissue edema is great. In addition, with the influence of cold, the vessel spasms develop, the bloodstream slows down and the tissue ischemia is growing. Physical rehabilitation after the action of the cold should be carried out very actively. Its success is associated with the complexity and perseverance of the use of therapeutic physical culture, massage, and various physiotherapy.

Posture, appearing in the usual pose of a man, is of great biological importance. Features of posture are associated with the state of the neuromuscular system, psychological features, elasticity of intervertebral discs, and functional properties of the spine and pelvis. It is a complex marker, allowing to estimate overall health. When it is normal, then the condition usually is not serious. Changing posture takes place throughout life. The basis of the appearance of posture disorders can be long-term, not physiological postures when the musculoskeletal system is experiencing a strong load. Challenging posture in both planes negatively affects health. The appearance of posture disorders associated with changing the physiological bends of the spine, worsen the state of health. The curvature of the spine is called scoliosis. It is a severe progressive disease of the spine that occurs quite often and is a lateral bending and twisting of the vertebrae around a vertical axis. Changes in the spine on the background of aging often strongly violate posture. Older people gradually form rounded back and increased cervical and lumbar lordosis, which significantly violates the general health of the person and reduces the forthcoming life expectancy.

For the long-term preservation of the optimal physical status of a person, regular physical activity is required. Rational muscle activity can stimulate the entire body. It increases oxygen consumption and accelerates the release of toxic products, stimulates metabolism and protein synthesis. Frequent feasible physical training inhibits the development of pathological changes in the nervous system and internal organs. Systematic physical training has a strong healing effect on the musculoskeletal system and activates the entire endocrine system. With regular exercise, blood and venous pressure are normalized and lymph circulation is enhanced. Physical activity normalizes the processes of humoral regulation in all body systems. The most pronounced positive effect develops in the case of a combination of feasible exercises that stimulate different muscle regions. This leads to the activation of biosynthetic processes in all cells of the body. Regular dosed physical activity with optimal nutrition and sufficient sleep has a strong stimulating effect on physical capabilities and mental performance.

The properties of erythrocytes strongly determine the course of the entire microcirculation and metabolism in the body. Elucidation of the state of students who had long-term low physical fitness and began to regularly perform feasible physical exercises can track the progress of optimization of erythrocyte parameters that are significant for microcirculation. The study involved 42 male students who had low physical activity throughout their future life and who began regular athletics training 3 times a week. The control group included 46 students who, for at least 7 years, regularly experienced athletics loads at least 3 times a week. The work uses standard proven biochemical, hematological, and statistical research methods. After six months of physical training in the blood of students, previously poorly physically trained, normalization of metabolites of arachidonic acid, a decrease in the amount of cholesterol and acyl hydroperoxides in erythrocytes, and an increase in the level of phospholipids in them. During these periods, the students who started training experienced an increase in the number of erythrocytes-discocytes and a decrease in the number of all altered forms of erythrocytes. For students with low physical activity, who began regular physical training, a gradual improvement in the surface properties of erythrocytes is characteristic, which facilitated the processes of microcirculation in tissues.

Regular execution of movements while in the aquatic environment, ensuring the swimming process, heals the entire body. As a result of regular swimming, many positive changes occur in human tissues. As a result of systematic swimming training, a functional improvement of all human internal organs occurs. Frequent swimming training improves health and enhances the severity of physical and mental performance. Swimming strengthens the heart, improves vascular function, trains skeletal muscles, activates immunity, stimulates the breathing process, neutralizes most of the effects of stress, and tones all body tissues. Swimming is considered as a dosed physical activity that forms a stable positive emotional background and leads to the recovery of the whole organism. In the central nervous system, during the performance of motor actions in the aquatic environment, a more pronounced intensification of life processes occurs than during the performance of physical exercises on land. This effect is possible due to the stimulation of skin receptors with water. Private swimming training stimulates the autonomic nervous system. Swimming weakens the activity of its sympathetic part and increases the biological capabilities of its parasympathetic component. This contributes to the normalization of peripheral vascular tone, optimizes heart rate, lowers blood pressure, stimulates gas exchange processes, contributing to an increase in oxygen content in the blood, and intensifies metabolism in all cells.