Hypothermia may be caused by physiologic factors, or it may be considered to be caused by pathologic factors, such as hypothyroidism and heart disease. 1. Physiological factors: prolonged exposure to cold temperatures and cold environments, lack of attention to the body’s protection against the cold and warmth, the body produces less heat and dissipates more heat, resulting in hypothermia. Low intake of food, excessive fatigue, bad weather and prolonged cold water immersion can also lead to hypothermia. 2. Pathologic factors. (1) Hypothyroidism: Patients with hypothyroidism may develop hypothermia due to slow body metabolism. (2) Heart disease: Long-term chronic heart disease leads to insufficient blood supply to the body, the body’s heat production is reduced, so the body temperature is low. In addition to this, cerebrovascular disease, anorexia nervosa, and excessive use of antipyretic drugs may also lead to low body temperature. Patients with low body temperature are advised to take precautions to protect themselves from cold and warmth, take hot water and give hot food to help raise their body temperature. If the body temperature does not rise, it is necessary to go to the hospital for relevant examinations to find out whether the low body temperature is related to certain diseases and to treat the primary disease.