In the past few days, most parts of the country have continued to experience high temperatures, and people have lamented: In such a hot day, air conditioning is responsible for life! Prolonged exposure to high temperatures is dangerous - "heat stroke" is an important keyword.

What would you like to say is the hottest thing recently?

Of course it’s the weather!

In the past few days,

most parts of the country have continued to have high temperatures.

People have lamented:

On such a hot day,

life is caused by the air conditioner!

In fact,

"hot to death" is not just a casual comment!

Prolonged exposure to high temperatures is very dangerous

-

" heat stroke " is an important keyword.

It is understood that

many of the deaths caused by high temperatures

were caused by "heat stroke."

What is heat stroke?

Heat stroke, also known as severe heat stroke, is a very dangerous emergency with a very high mortality rate of 40% to 50%. For people over 50 years old, the mortality rate even reaches about 70%.

The human body has a body temperature regulation center , which under normal circumstances regulates the balance of heat production and heat dissipation in the body to maintain the body temperature at around 37°C.

But in some cases, this balance of production and heat dissipation will be broken, causing heat to accumulate in the body, causing heat stroke.

Generally speaking, human body heat dissipation mainly relies on radiation, evaporation and a small amount of convection and conduction.

When the ambient temperature is higher than the skin temperature, the human body can only rely on evaporation and sweating to remove heat. However, when the temperature is too high, the heat dissipation capacity will decrease (this phenomenon is called sweat failure), and heat accumulation will occur in the body, resulting in The organs, especially the brain, "go out of control" and heat stroke occurs.

Heat stroke is caused by the rapid accumulation of heat in the body. Patients often experience symptoms such as local muscle spasm, high fever, no sweat , dry mouth, coma, difficulty breathing, and even respiratory failure, which is the most fatal form of heatstroke.

In addition to individual factors, the incidence of heat stroke is closely related to three factors: high temperature, high humidity and a closed, windless environment.

Heat stroke is generally mild, with body temperature often exceeding 38°C, accompanied by facial flushing, profuse sweating, burning skin, nausea and vomiting, or cold limbs, pale face, decreased blood pressure, and rapid pulse.

and The difference between heat stroke and heat stroke is that it manifests as high fever (rapid rise in body temperature), often no sweating, and even coma and shock.

Heat stroke is usually accompanied by a body temperature as high as 40°C or above.

What happens when the body temperature reaches 40°C?

As we all know, the highest scale of a thermometer reaches 42°C. Will people be "burned to death" if the temperature exceeds this temperature?

When the human body temperature is 37°C, the body's heat production and heat dissipation are relatively balanced, and the body's functions are the most stable. can also have an adjustment mechanism when body temperature rises, but when it exceeds a certain limit, it will lead to organ intolerance and organ failure.

For example, for the heart, when the body temperature exceeds 37°C and gradually rises to over 40°C, the cardiac output will double, and the oxygen consumption will also increase by about 40%.

But when the body temperature reaches 42°C, cardiac output and oxygen consumption will suddenly decrease, and myocardial necrosis will occur.

This is caused by ultrahigh temperature exceeding the tissue tolerance limit, causing organ failure. Obviously, this is life-threatening.

When a fever reaches 39°C, one would almost become suspicious of life. What kind of disease can cause a fever to reach 42°C? The answer is heat cramps, heat exhaustion and heat stroke. Heat stroke is the most serious.

Which groups of people

should pay special attention to heat stroke?

Heat stroke is most likely to occur in the elderly, children, pregnant women or people with underlying diseases (such as cardiovascular and cerebrovascular diseases, obesity).

The body functions of the elderly decline, and cardiac output cannot be adjusted in high temperature environments, leading to heat stroke due to circulatory disorders. Children often suffer from heatstroke due to poor sweat response.

In addition, people with colds, fever, gastroenteritis diarrhea and hypokalemia are also prone to heat stroke.

How to provide correct rescue if heat stroke

occurs?

Immediately transfer the patient to a cool and ventilated place, then let him lie down, physically cool him , replenish water (salt water is best), etc. At the same time, call 120 for emergency treatment in time, and the treatment cannot stop during the emergency treatment.

How to prevent heat stroke?

Outdoors, the main objective factors that affect people's heat stroke are: daily average temperature, relative humidity and maximum temperature.

If the daily average temperature is >30°C and the relative humidity is >73%, the probability of heat stroke will show an obvious upward trend. If the maximum temperature is ≥37°C, the number of people suffering from heat stroke will increase dramatically. If you meet two of the conditions before going out, you should pay attention.

In addition, it should also be noted that the alternation of hot and cold can also easily lead to heat stroke. The body cannot adapt to it all of a sudden, and there may also be body temperature regulation disorders, water and electrolyte balance imbalances, and heat stroke neurological disorders.

For people who need to work outside for a long time or whose working environment is hot and airtight, it is best to prepare some salt water, ice cubes, etc. in advance.

In addition, when people suffer from heat stroke, they usually show signs of heat stroke, which generally include symptoms such as headache, dizziness, thirst, excessive sweating and weakness in the limbs.

If it is moved to a cool and ventilated place in time, physically cooled down and replenished with water (salt water is best), it can recover in a short time.

Pay attention to getting enough sleep and drinking plenty of water. When there is a high temperature warning, go out as little as possible.

reminds everyone again:

When the symptoms of heat stroke are severe,

must not be careless,

it can really kill you!

must be careful!

Source: Popular Science China (ID: Science_China)

Author: Wang Xiaohuan (Ph.D. of Fudan University)

Producer: Li Daixiang

Editors: Chen Zixia, Xu Xiangda

Internships: Wu Xiaowei, Xu Yiming

Be careful when going out!