Shanghai Central Meteorological Observatory issued a yellow warning signal of high temperature at 08: 20 on July 8, 2022: Due to the influence of subtropical high, the temperature in this city is rising rapidly at present. It is estimated that the highest temperature in this city will exceed 35℃ today. Please do a good job in heatstroke prevention and cooling.
High temperature warning
—— Pay attention to heatstroke during the hot summer—
Heatstroke is the thermal damage of the body caused by the accumulation of heat in the body when the individual exposed to the high temperature and high humidity environment (or the environment temperature is not high but there are heat dissipation obstacles) produces more heat than heat dissipation. The heat dissipation modes of the machine body include conduction, convection, radiation and evaporation. When the way of heat production and heat dissipation is balanced, the body temperature can be kept normal and stable; When heat production is greater than heat dissipation, the accumulation of heat in the body leads to the increase of core temperature and excessive sweat loss, which can lead to heatstroke. Core temperature change = body heat generation-(conduction heat dissipation+radiation heat dissipation+convection heat dissipation+evaporation heat dissipation) What kind of heat dissipation form the human body takes mainly depends on environmental conditions. Conduction, radiation and convection require a temperature difference between the skin and the environment. When the ambient temperature approaches or exceeds the skin temperature, evaporation is the only way to dissipate heat, and the amount of sweating increases obviously, which is prone to heatstroke. High humidity environment affects sweat evaporation and heat dissipation, which is also one of the reasons for heat accumulation in the body. When all four heat dissipation methods are affected, heatstroke is easy to occur.
Dear teammates, do you know anything about heatstroke?
Heatstroke is usually divided into premonitory heatstroke, mild heatstroke and severe heatstroke, among which severe heatstroke can be divided into heat spasm, heat exhaustion and heatstroke.
According to the diagnostic criteria of heatstroke, it was graded from three aspects: core temperature, consciousness change and clinical manifestations.
Mild heatstroke: that is, threatened heatstroke in the previous definition. Only the above symptoms of heatstroke, normal or slightly increased core temperature (< 38℃), no new disturbance of consciousness, no organ damage.
Moderate heatstroke: heat exhaustion. There is decompensation of organ dysfunction, and it can not meet the diagnostic criteria of heat stroke. It is often characterized by manifestations of insufficient blood volume, such as cold and wet skin, pale face, obviously increased heart rate, decreased blood pressure, oliguria, etc. You may have syncope, but you will regain consciousness within a few minutes without obvious neurological damage (GCS score = 15). Core body temperature increased (≥38℃, < 40℃).
Severe heatstroke: that is, heatstroke. After exposure to high temperature (high humidity) environment and/or strenuous exercise for a certain period of time, any of the following clinical manifestations appears, which cannot be explained by other reasons: ① central nervous system damage (such as coma, general convulsion, delirium, abnormal behavior, etc., GCS score ≤ 14); ② Core temperature ≥ 40℃; (3) multiple organ (≥2) dysfunction (liver, kidney, rhabdomyosis, gastrointestinal, circulatory and respiratory dysfunction, etc.); ④ Severe coagulation dysfunction or disseminated intravascular coagulation (DIC).
How should we deal with heatstroke?
1. Immediately terminate the training;
2. Move to a ventilated and cool place to rest;
3. Help heatstroke comrades to take off their equipment and coats, fan and sprinkle water for him to promote heat dissipation;
4. Drink 500-1000ml； of light salt water;
5. In the wild, you can use the surrounding trees and terrain to shade the sun, use your own kettle to get water, and even help your teammates immerse themselves in the water to cool down (avoid immersing your head in the water to avoid respiratory obstruction);
6. When the symptoms of heatstroke are still not improved after rest and drinking water, you should immediately ask the health personnel for help.
How to effectively prevent heatstroke in summer training?
Before training: half an hour before training, 200 -500ml； of boiled water or mineral water can be taken orally;
Training: In case of high temperature weather, sweating more, thirst, less urine and dark urine, light salt water should be replenished in time. Especially when there is weakness, numbness of hands and feet, dizziness, muscle spasm of limbs, etc., normal saline should be added immediately, or water and pickles should be added;
After training: add brackish water, pickles and slightly salty soup in time.
"Hot acclimatization" training, find out.
Thermal acclimatization is a special training to adapt to high temperature and high humidity environment based on physical training, which should be carried out every year before entering summer (mid-April), especially when the local temperature suddenly rises.
The temperature of thermal acclimation environment should be higher than 30℃. If the temperature is not enough, local high temperature environment can be created by increasing clothes. Thermal acclimatization requires continuous training for 10-15 days, 1.5-2 hours a day, and the exercise time can be reached in several times, but each time it should not be less than 50 minutes.
Training can be carried out through various forms of aerobic exercise, such as long-distance running, basketball, football and other ball games, with or without load training, etc. Training must reach a certain intensity, such as heart rate reaching 130-150 beats/min, sweating, etc.
After heat acclimatization training, the body’s body temperature regulation and organ protection ability can be greatly enhanced.
Choose a scientific and reasonable training opportunity
Personal factors: Know your physical condition before training and do what you can. Especially for those who are not systematic in early training, have fever, diarrhea, stay up late, etc., we must scientifically allocate physical fitness and make a reasonable plan.
Environmental factors: evaluate the environment before training. The meteorological threshold of heatstroke is daily average temperature > 30℃ or relative humidity > 73%. When the conditions of temperature and humidity coexist or one of them increases obviously, the incidence of heatstroke increases. When the daily maximum temperature is ≥37℃, the number of people suffering from heatstroke increases sharply.
Training factors: When the environment is hot and humid, when the probability of heatstroke increases, the training intensity should be adjusted reasonably, and comfortable and breathable clothes should be worn during training, and the rest time should be arranged reasonably before and after training. When arranging training, we should pay attention to strengthening medical support, carrying heatstroke prevention and cooling drugs, oral rehydration salts, commonly used injections and drugs, and carrying ice packs, thermometers and pulse oximeters for monitoring.
Tips of "Cool" for heatstroke prevention and cooling in summer.
Heatstroke is very common in the training of fire fighting in summer. It looks like a minor illness, but it also hides a big hidden danger. You must not take it lightly. In addition to the series of related knowledge mentioned above, I have a little hint:
Teammates can’t simply drink a lot of mineral water or pure water after training, so they must pay attention to the supplement of electrolytes.
Because a lot of sweating will cause a lot of electrolyte loss, simple hydration will cause low potassium and sodium, which will cause weakness, numbness of hands and feet, and in severe cases, heat spasm, coma, and even cardiac arrest, so timely supplementation of light salt water is the best choice.
Original title: "Today’s Shanghainese collective" sauna "mode, how far are you from heatstroke? 》