With the arrival of summer, the weather is getting hotter and hotter, and from time to time, heat stroke occurs. The Chinese newspaper of Chinese medicine also gives timely solutions in case of heatstroke. The newspaper recommends that “scraping can save the day in case of heatstroke”. Is gua sha really an effective measure for heat stroke first aid? The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. Human is a constant temperature animal, and the normal human body temperature is maintained at about 37°C. The normal body temperature is the result of the balance between heat production and heat dissipation of the body. The human body generates heat during physiological activities, and the heat generated during strenuous activities increases exponentially. The human body dissipates heat mainly through the following ways: 1. Radiation: about 60% of the heat dissipation. When the room temperature is 15～25℃, radiation is the main way of heat dissipation in the human body. 2.Evaporation: about 25% of the heat dissipation. But when the ambient temperature exceeds the skin temperature radiation heat dissipation is blocked, heat dissipation mainly depends on evaporation that is sweating, evaporation 1L sweat, can dissipate 2436kJ (580kcal). But when the humidity is greater than 75%, evaporation is significantly reduced. 3.Convection: 12% of the body’s heat dissipation is accomplished by convection, and the speed of convection heat dissipation depends on the temperature difference between the skin and the environment and the air flow rate, so the use of electric fans to increase the air flow can promote heat dissipation when treating heat stroke patients. 4.Conduction: Under normal circumstances, the human body is generally in direct contact with the air, because of the poor thermal conductivity of air, so conduction only accounts for about 3% of heat dissipation. However, if the human skin is in direct contact with water, the heat dissipation rate reaches 20 to 30 times the normal rate because of the strong heat conduction of water compared to air (remember that this is very important for understanding the first aid of heat stroke). When the body produces too much heat and heat dissipation barriers will be heat accumulation in the body and lead to heat stroke. The main damage caused by heat stroke is that high temperatures can damage the brain, heart, kidneys and other organs causing dysfunction of these organs and in severe cases can cause death. The severity of damage caused by heat stroke is positively correlated with the level of body temperature and the duration of action: that is, the higher the body temperature, the longer the duration of high body temperature, the more severe the damage. Therefore, it is not difficult to understand that emergency cooling is the most important therapeutic measure, and the speed of cooling determines the patient’s prognosis. Cooling methods: The patient is placed in water between 27 and 30 degrees Celsius (also recommended to be placed in water at 4 degrees Celsius or 10°C) for rapid cooling by conduction, or the patient can be wrapped in wet sheets or wet clothes and given a strong fan to increase conduction and convection cooling.