Heat exhaustion is also known as heat exhaustion. Its pathogenesis is mainly due to heat exhaustion, which may also be accompanied by excessive sweating, water loss and salt loss. The human body is not adapted to the hot environment, which causes excessive loss of fluids and electrolytes, leading to peripheral vasodilation and insufficient circulating blood volume, thus causing low blood volume and electrolyte imbalance, resulting in collapse. It often occurs in the elderly, children and patients with chronic diseases. In severe heat stress, the circulation capacity is insufficient due to excessive loss of body fluids and body sodium. It manifests as sweating, fatigue, weakness, dizziness, headache, nausea, vomiting and muscle cramps, and there may be obvious signs of dehydration: tachycardia, orthostatic hypotension or syncope. The body temperature is slightly elevated, and there is no obvious sign of central nervous system damage. Depending on the severity of the disease, examinations can show increased hematocrit, hypernatremia, mild azotemia and abnormal liver function. If not treated in time, it may develop into heat stroke.