Don't take the hot weather lightly, heat stroke is not a trivial matter

Author: Wang Changyuan, Chief Physician, Xuanwu Hospital, Capital Medical University

Reviewer: He Jingyu, Chief Physician, Xuanwu Hospital, Capital Medical University

As summer approaches, the weather is hot, and the temperature and humidity have increased significantly. Staying in a high-temperature environment for too long is prone to heatstroke. So what is heatstroke? Heatstroke refers to a clinical syndrome in which the body's temperature regulation center is dysfunctional under high temperature conditions, causing water and electrolyte metabolism disorders, leading to dysfunction of the central nervous system and cardiovascular system. Every year, the mortality rate of severe heatstroke in my country is as high as 10% to 15%. When it develops into heat stroke, the mortality rate can be as high as 50% or more. Therefore, don't take the hot weather lightly. Heatstroke is not a trivial matter. Severe heatstroke can lead to death.

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1. Clinical manifestations of heat stroke

Heatstroke can be divided into premonitory heatstroke, mild heatstroke and severe heatstroke according to the severity of clinical manifestations. Premonitory heatstroke refers to symptoms such as thirst, sweating, dizziness, chest tightness, palpitations, nausea and weakness in the limbs in a high temperature environment, and the body temperature generally does not rise. In addition to the symptoms of premonitory heatstroke, patients with mild heatstroke are often accompanied by an increase in body temperature, which can reach above 38.5℃, and symptoms such as flushing and burning skin may also appear. It may also manifest as cold and wet skin, nausea, vomiting, increased pulse and decreased blood pressure. Severe heatstroke can be divided into three types: heat cramps, heat exhaustion and heat stroke. Heat cramps refer to muscle cramps after strenuous activities and heavy sweating in a high temperature environment, without obvious increase in body temperature. It is one of the early manifestations of heat stroke. Heat exhaustion often occurs in children and the elderly. These people have decreased thermoregulation function, reduced heat dissipation ability, and excessive loss of body fluids and sodium, which causes insufficient blood volume in the body's circulation, resulting in symptoms such as tachycardia and hypotension. Laboratory tests may show hypernatremia and abnormal liver function. If not treated in time, it may further develop into heat stroke. Heat stroke is the most serious type of heat stroke. It is mostly caused by patients staying in a high-temperature, poorly ventilated environment for too long, causing excessive accumulation of heat in the body, leading to multiple organ dysfunction. It is often manifested by high fever, coma, convulsions, delirium, abnormal behavior and other disturbances of consciousness.

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Heat stroke can be divided into classic heat stroke and exertional heat stroke. Classic heat stroke is more common in the elderly, weak and those with chronic diseases. The dysfunction of temperature regulation causes reduced heat dissipation. It usually starts gradually, and the prodromal symptoms are hidden and difficult to detect. It gradually progresses to apathy, delirium, coma, etc. The body temperature can reach 40-42℃, and incontinence may occur. Exertional heat stroke is common in healthy people who exercise vigorously in the summer, such as soldiers in training, firefighters and construction workers who work outdoors. After working in a high temperature and high humidity environment for a period of time, they experience extreme fatigue, headache, pale face, nausea, vomiting and syncope. The body temperature rises rapidly to above 40℃, and there are manifestations of central nervous system damage such as convulsions, delirium and coma. After that, rhabdomyolysis and liver and kidney failure may occur. If not treated in time, the condition deteriorates rapidly and the mortality rate is extremely high.

2. Prevention and treatment of heat stroke

So, how to prevent heatstroke in the hot summer? First, avoid staying in high temperature, high humidity and closed and unventilated environments for too long, and try to avoid strenuous physical activities or sports in high temperature and high humidity environments; secondly, infants, children, the elderly and people with chronic diseases should pay attention to keeping indoor ventilation. Drink plenty of water in hot weather, and don't wait until you are thirsty to drink water. You can drink light salt water appropriately to make up for the salt lost by sweating. Avoid outdoor activities alone in hot weather. Use a parasol or wear a sun hat when doing outdoor activities. If you feel unwell, call your companions for help in time. When the weather is hot and humid, keep the room ventilated or turn on the air conditioner to cool down.

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When heat stroke occurs, the patient should be quickly transferred to a cool, ventilated place, kept lying flat, unbuttoned, and fanned to accelerate evaporation and convection heat dissipation. If the patient is conscious, he or she can take some refreshing drinks orally. If conditions permit, cold water or alcohol can be used for full body baths or ice cubes can be placed in the armpits, head, and groin where the large arteries are clearly pulsating to accelerate heat dissipation. In case of severe heat stroke, call 120 emergency number immediately, wait for professional medical personnel to rescue and send to the hospital for further diagnosis and treatment. If respiratory and cardiac arrest occurs, perform cardiopulmonary resuscitation immediately.

References

【1】Zhong Lincui, Song Jingchun, Gao Yan, et al. Analysis of risk factors for heat stroke in patients with heat stroke[J]. Trauma and Critical Care Medicine, 2022, 10(2): 97-99, 104.