Winter to Summer and Vice Versa: Consequences for Different Age Groups Introduction: The Challenge of Chronobiology and Adaptation Quick changes in climate and time zones (jet lag) combined with extreme seasonal changes represent a powerful stress for all regulatory systems of the body. This is not just "acclimatization," but a comprehensive restructuring of circadian rhythms, thermoregulation, vegetative tone, and immune response. The consequences of such a transition differ fundamentally for children, adults, and the elderly due to age-specific physiological characteristics and adaptive reserve. Physiological Basis of Stress: More Than Just Temperature Change The body is faced with a triple blow: Disorientation of circadian rhythms. A failure in the "internal clock," located in the suprachiasmatic nucleus of the hypothalamus. The production of melatonin (sleep hormone), cortisol (stress and alertness hormone), and digestive enzymes is disrupted. The body continues to live in "winter" mode when it's "summer" outside, and vice versa. Extremal thermoregulatory shock. An emergency reconfiguration of the heat exchange system is required: from working in conditions of cold stress with maximum heat preservation to a cooling mode through sweating and expansion of peripheral vessels, which creates a load on the cardiovascular system. Immunological provocation. A sharp change in the environment (new allergens, pathogens, temperature) temporarily reduces the effectiveness of the immune response, increasing the risk of respiratory and intestinal infections ("traveler's diarrhea"). Age Groups: Differential Analysis of Risks 1. Children (especially preschool and elementary school age) The child's body has high plasticity, but its regulatory systems are still immature. Consequences: The manifestations are bright and fast: sleep disorders (the child confuses day and night), moodiness, disruptions in appetite and digestion, possible fever due to stress. Especially dangerous for ba ... Читать далее