For every 1°C drop in body temperature, immunity drops by 30%? 37℃ has become history, how good is the body temperature?

Have you ever had such doubts? Obviously, the normal body temperature of healthy people is 37°C, but most people measure their body temperature in daily life, and they are all lower than 37°C, mainly fluctuating between 35°C and 36.7°C. Why?

In fact, Stanford University School of Medicine has long found that compared with the past (since the 19th century), the average body temperature of adults has been falling, from 37 ℃ to 36.6 ℃ . So why does our body temperature keep dropping?

1. Why is the body temperature of most people lower than 37℃?

Do you know how normal body temperature comes from? This is the conclusion drawn by a German doctor named Carl Wunderlich who measured the underarm body temperature of 25,000 people by using a thermometer up to 12 inches (about 30cm) in length.

In modern research, the sublingual temperature is mainly measured at present, and it is found that only 8% of them have a normal body temperature (sublingual) of 37 °C, and the overall average body temperature is 36.8 °C . It can be said that 37 °C has become history.

In addition to the drop in body temperature, in fact, the body temperature is not always fixed, it is constantly fluctuating.

Generally speaking, the normal body temperature is between 36.5 ℃ and 37.2 ℃, and it is a fever if it exceeds 37.3 ℃ .

However, the measured values ​​are different depending on the location selected for measurement. For example, the normal sublingual temperature of the oral cavity is 36.3°C-37.2°C, the rectal temperature is 36.5°C-37.7°C, the armpit temperature is 36°C-37°C, and the ear temperature is 36.3°C-37.2°C. 35.7℃-37.5℃.

In addition, body temperature can be affected by various factors such as day and night, age, gender, activity, drugs, etc. For example, the body temperature will be lower in a static state and before eating; and the body temperature will be slightly higher after exercise and after eating. But the range is very small, generally not more than 0.5 ℃ ~ 1.0 ℃.

Therefore, in general, as long as the body temperature does not exceed the standard range too much, you don't need to worry too much.

2. The higher the body temperature, the stronger the immunity?

There is a lot to say about body temperature. Scientists once said that for every 1 degree Celsius drop in body temperature, immunity will decrease by 30% . In addition, Professor Wang Xiaochuan of Tongji Medical College of Huazhong University of Science and Technology also said that within the normal body temperature range, the higher the body temperature, the stronger the immunity.

A study was also published in the journal " PNAS " not long ago, showing that a moderate increase in body temperature will well enhance the metabolic process and anti-tumor function of CD8+ effector T cells, and improve the body's immunity.

However, a recent study by the Chinese Academy of Sciences published in "Nature Metabolism" recently gave a different answer. The study found that compared with metabolic rate, body temperature has a greater impact on lifespan, and maintaining a lower body temperature has a greater impact on lifespan. Conducive to longevity .

In this study, black-lined hamsters were used as experimental subjects, and they were divided into two groups, one group was kept in an environment of 32.5 °C (group a), and the other group was raised in an environment of 21 °C (group b).

The results showed that the average body temperature of the hamsters in group a was 0.5°C higher than that in group b, the average metabolic rate was 40% lower, and the lifespan was shorter. However, if it can be kept ventilated at high temperature, it can also reduce body temperature and prolong life .

That is to say, it is best for people to stay in a constant temperature environment, otherwise, if they continue to stay in a high temperature environment, they may really "heat" to death. Of course, whether it's a drop or a rise in body temperature, as long as it stays at the right level, that's fine.

3. How high will a person's body temperature be to die?

It is not impossible to be "hot" to death. The existing human body temperature limit is 46.67 ℃ . If this temperature is exceeded, it will really endanger life.

The core body temperature of a normal human body is maintained at about 37°C. According to the degree of fever, it can be divided into low-grade fever (37.3°C to 38°C), moderate fever (38.1°C to 39°C), high fever (39.1°C to 41°C), and ultra-high fever. (above 41℃).

In the process of increasing the body temperature, the body will also undergo some changes, as follows:

1. Burn to 37.5℃

At this time, the thermoregulation center of the hypothalamus can sense the signal of "body heat", and in order to dissipate heat, it will make the body's heat dissipation system "work overtime".

At this time, the skin will secrete a lot of sweat, causing water loss, so people will feel very thirsty, and the blood flowing to the brain will also decrease at this time, so many people will feel headache, dizziness, and unable to concentrate.

2. Burn to 38℃

In order to continue to dissipate heat, the capillaries are further expanded, resulting in reddened face and hot skin. At the same time, due to the decreased activity of various enzymes in the body, people will also become weak and tired , and some people will also feel hot and cold. .

3. Burn to 40℃

At this time, the skin is as hot as the fire, and it is amazingly hot. In order to better dissipate heat, the blood of the whole body will be more arranged to the bones and skin, so that the blood flow of the internal organs will be reduced, including the heart function and the brain, which will lead to people's blood flow. Consciousness begins to blur .

At this time, you may perform some behaviors that are very different from usual, such as being unable to control your emotions, getting angry easily, and some hallucinations.

4. Burn to 42℃

At this time, organs such as the heart, liver, and kidneys will be damaged, the cells of the whole body will be irreversibly damaged and failed, the various organ systems of the body will also be "abandoned", and the human body will face life-threatening.

Therefore, everyone should pay attention to control their body temperature. And recently, the temperature has continued to climb, and some people who are engaged in heavy physical strength or work in a high temperature environment.

In particular , people with malnutrition, old age, frailty, chronic diseases, etc. , should pay attention to preventing heatstroke, and cool down in time when symptoms such as headache, dizziness, palpitations, elevated body temperature, nausea, vomiting, and cramps occur.

Whether it's a drop or a rise in body temperature, as long as it stays at the right level, it's fine. If the body temperature is too high, it is necessary to cool down in time, drink more water, rest more, and conduct physical cooling reasonably (such as using antipyretic patches or cold towels), etc.

If the situation is more serious, it is best to go to the hospital as soon as possible to find out the cause, and use antipyretics or anti-inflammatory drugs as prescribed by the doctor to avoid "burning" the body.

References:

[1] "If a person's body temperature continues to rise, how many degrees will it burn to death? 》. Tencent Medical Code. 2022-05-04

[2] "It's no longer 37°C, the body temperature of human beings has generally dropped, how much is the body temperature to be considered healthy? 》. Health Times. 2022-03-24

[3] "Seriously, will a fever burn the brain? If you still take fever as a bad thing, you should really see it". Popular Science China. 2019-01-17

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