Do you know what the minimum body temperature that humans can withstand?
Under normal circumstances, the body temperature of a person is around 37℃, and the external temperature is around 20 degrees Celsius, which can cause a drop in the body temperature. When the body temperature is too low, it can lead to abnormal heartbeat and loss of consciousness.
Theoretically, the minimum limit for human body temperature is 0℃. At this temperature, human tissues will freeze and cells in the body will be destroyed. The world's lowest temperature record is 13.7℃
at Anna Bagenholm, but some studies have found that 37℃ is no longer the standard body temperature in the human body. What is going on? What does it mean to humans?
1. Why is 37℃ the "dividing line" of human body temperature?
For a considerable period of time, 37℃ (98.6 degrees Fahrenheit) has been used as the temperature standard for human health, but this standard has been constantly questioned.
7 ℃ standard body temperature is derived from the research results of German doctor Carl Reinhold August Wunderlich in 1851. At that time, by measuring the body temperature of 25,000 patients millions of times, summarized that 37 ℃ is the "physiological point" of normal body temperature .
But at present, many studies have found that human body temperature is constantly decreasing.
In January 2020, published in eLife, a study from Stanford University in the United States, researchers compared the temperature records of federal army veterans after the American Civil War with the National Health Survey of the early 1970s and the Stanford clinical data platform in the early 21st century.
The final result found that the body temperature of men born at the beginning of this century was 0.59 degrees Celsius lower than that of men born about 200 years ago, while women's body temperature has dropped by 0.32 degrees Celsius since the 1890s.
In October of the same year, it was published in Science Advances from a research team led by the University of California, Santa Barbara. Researchers also discovered a phenomenon of a decrease in human body temperature in a relatively remote indigenous tribe in Bolivia. What exactly causes the body temperature to drop? Researchers at Stanford University believe that there are two reasons:
First, it is related to the reduction of inflammation . Inflammation will produce various protein and cytokines to increase the temperature of the human body. With the advancement of medical level, inflammation in the human body has improved;
Second, it is related to the ambient temperature . Modern people have changed the environment through electrical appliances, reduced energy consumption, and the body temperature also changes accordingly.
In addition, in a new study published in Current Biology, researchers from Harvard University in the United States gave another explanation: changes in human body temperature may also be related to a significant reduction in physical activity.
2. Does the body temperature drop affect humans?
The human body's "factory temperature" is set to about 37℃, However, due to the influence of time, hormones, age, emotions, etc., the body temperature will change .
At this time, the human skin receptors will transmit cold and heat signals to the hypothalamus, and the hypothalamus will give instructions for blood vessel contraction or expansion to help the body produce heat or dissipate heat. Through the "automatic temperature control of human body" system, the body temperature can be kept within the temperature range.
So is it better to have a high body temperature or low?
The body temperature has a relatively safe range. When the body temperature changes from the normal temperature are 3-5℃, it has no significant impact on most functions of the human body.
However, high fever will cause certain damage to the tissues of each organ, and too low may lead to low immunity. Japanese doctor of medicine, Yuki Ishihara, once mentioned in "36.5℃ to determine health" that for every 1 degree drop in , immunity will be reduced by more than 30%.
Body temperature and immunity are also related?
Studies have found that body temperature is linked to basal metabolic rate. For every 1℃ increase in body temperature, basal metabolic will increase by 13%.When the body temperature is high, the blood flow rate is fast, and leukocytes can detect abnormalities in the body more quickly and kill pathogens. On the contrary, if the body temperature is too low, the blood flow slows down, the white blood cell work efficiency decreases, and the immunity will also decrease.
3. Research has found: People with less fever are prone to cancer?
There are some people who seem to have few fevers all year round. Does this mean that they are in good health or not? A study published in the journal PNAS found that fever can enhance the mitochondrial mass and metabolic activity of CD8+ effector T cells, and can significantly enhance the human body's ability to anti-tumor . In this case, people who often have fever have stronger anti-tumor ability?
First, let’s first understand why people have fever.
generally causes fever in human body, infectious fever, such as viruses, fungi, parasites, etc.; the other is non- infectious fever, including rheumatoid immune system diseases, dehydration fever, tumor diseases, etc.
At this time, the "illegal molecules" in the body are causing trouble, and the white blood cells will produce a bunch of cytokine to counter, thereby causing the body to have fever. In other words, fever is a manifestation of our body activate the defense mechanism .
What does it mean that you have very little fever?
People do not have a fever. It is possible that the "criminals" in the body did not attract enough attention from the white blood cells. At this time, the defense mechanism was not awakened and the body temperature would not rise.
rarely has fever, which does not mean poor immunity. has frequent fevers, which may also be because the body's immune mechanism is more sensitive, which is not directly related to cancer . The research of "PNAS" is based on animal experiments and in vitro cell experiments. Whether the same data can be obtained in the human body needs further analysis.
Fever is a manifestation of the body's immune response. Therefore, when you encounter fever, do not rush to take medicine. You should first distinguish according to the degree of fever. If the temperature is not higher than 38 degrees Celsius, you only need to drink water, pay attention to nutritional supplements, and observe at home. However, if the body temperature has not declined for more than 3 days and the mental state is getting worse and worse, you need to go to the hospital for treatment in time.
Reference materials:
[1] "37℃ means a low fever! Why is the temperature of the human body getting cooler? Harvard Scientist: Lack of Activities. China Biotechnology Network. 2021-11-08
[2] "The secret of the human body's "constant temperature" is hidden in the ears, and 1℃ lower than 1℃ will harm immunity." Life Times. 2022-09-02
[3] "PNAS: Why do people who do not have fever for a long time are more likely to suffer from cancer? 》. Frontiers of Life Sciences.2021-10-11
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