What is the normal body temperature of human beings?
The human body is metabolized to produce heat all the time, exercise produces heat, and dissipates heat to the environment. The two maintain a constant body temperature. But warm-blooded animals, including humans, have the ability to regulate temperature through the brain’s body temperature center, which is located in the hypothalamic region of the human brain.
Therefore, the average body temperature of a person is not determined by cell metabolism, muscle movement, etc., but is “designed” by nature in advance.
Is the human body temperature 37 °C? To be precise, 37°C is the average temperature in the mouth of a healthy adult at room temperature at around 12 noon. This theory was first proposed by the 19th-century German physicist Carl Windridge.
In 1992, the British National Health Service system re-stated the body temperature of 148 people. The average body temperature of normal people was about 36.8 °C, and it fluctuated freely between 36.1 °C and 37.2 °C.
In addition, many studies have also found that individual differences in humans, age differences, different parts of the trunk, different times of the day, and some inflammatory reactions, etc., will fine-tune the individual’s temperature.
Assume that human normal body temperature has risen by one degree
For the Earth, because the energy provided by the sun has not changed, and all the energy flowing in the biosphere comes from the fixed solar energy of the producers, this part of the energy flowing through the ecosystem eventually dissipates in the form of heat and returns to the environment.
Even if the human body temperature rises, the food intake of the individual may increase (but the total solar energy fixed by the plant does not change), and the heat that it dissipates into the environment also increases. Therefore, the total energy should not change for the earth.
For nature, the species “person” belongs to the top of the food chain. An increase in body temperature means that the intracellular enzymatic reaction becomes more intense, so it seems that the basal metabolism does increase. This means that humans need to ask for more food and, of course, generate more calories.
And the result of more human metabolic activities is – global warming! However, how warm is it?
Seth Wennes, a researcher at Lund University in Sweden, wrote in the July 12, 2017 issue of the Journal of Environmental Research News that an average of one child can reduce carbon dioxide emissions by 58.6 tons per year.
In this way, if the human basal metabolism increases by 13%, each person’s carbon dioxide emissions will increase by 7.6 tons / year, while the global population (in 7.5 billion) of carbon dioxide emissions will increase by 57 billion tons / year! The greenhouse effect of so much carbon dioxide can not be underestimated.
For human society, because of the two premise of increased basal metabolism and increased carbon emissions, humans will be forced to grow more food crops, or, as Seth Wennes said, increase vegetarian intake. To reduce the loss of energy in the energy transfer chain, or to maintain a basic energy supply at the expense of “family planning” to reduce the population.
Assume that human normal body temperature drops by ten degrees
For the hypothesis that “if the average human body temperature drops by 10 °C”, when exploring human adaptation to the environment, it can be understood that the ambient temperature has risen by 10 °C. According to the human body’s tolerance to ambient temperature under normal conditions, we can imagine an increase in ambient temperature of 10 °C. Is such ambient temperature not suitable for human survival?
In summary, if the average human body temperature drops by 10 ° C, as the global “relative warming” intensifies, some “hot people” high temperature areas (such as 40 ° C high temperature Shanghai, etc.) will indeed be completely no longer suitable for human habitation.
In contrast, the body temperature of the comet is much higher than the normal human body, about 38-39.5 °C. Therefore, it is conservatively estimated that the comet will probably increase the intensity of the invasion and further occupy the earth.
Of course, the above problems are purely brain-opening, because the temperature of the human body is the result of interaction with the environment, and it is impossible to suddenly increase or decrease. What effect does human temperature change have on ourselves in the regulation of human body temperature? In fact, the change of basal metabolism is only one aspect, and some serious scientific research confirms that the truth is far more exciting than we think.
Can elevated body temperature reduce fungal infections in humans?
This is one of the few scientific insights around the topic “Why do we need to maintain a body temperature of 36.8 °C”. Some scientists believe that relatively high body temperature can make most fungi deterred in our bodies.
Professor Arturo Casa de Wall’s study confirmed that between 27 ° C and 40 ° C, for every 1 ° C increase in temperature, 6% of fungi lost the ability to infect the host. This is why there are tens of thousands of fungi that can infect warming animals such as reptiles and amphibians, but only hundreds of species that can threaten humans and other mammals.
However, the obvious drawback of increasing body temperature is that humans need to get heat from more food to maintain body temperature.
The authors also suggest that elevated body temperature also brings other benefits, such as maintaining physical activity, allowing mammals to escape from the claws of large hunters. After the extinction of dinosaurs, high body temperatures that are resistant to fungal infections make mammals the dominant organism on Earth.
However, there are still many controversies surrounding this theory. First, the impact of fungal infections on humans is actually unknown. It is true that some fungi are indeed pathogenic, but most fungi are harmless to the human body, so whether the mammal is really only to resist the fungus does not hesitate to raise the body temperature remains to be further verified.
In addition, if more food is needed to maintain body temperature, warm-blooded animals have to increase their foraging activity, thereby prolonging exposure to predation. Therefore, the consideration of the living environment is an indispensable part of the animal’s benefits and disadvantages of increasing body temperature.
Reduced body temperature and extended life?
More recent research reports have shown that hypothermia can prolong life.
In 2006, American scholar Bruno Conti published this article in the top academic journal Science. They specifically express a protein called uncoupling protein 2 in the vicinity of the preoptic area of the hypothalamus in the mouse’s thermoregulatory center. This protein can cause local temperature rise by releasing heat. The body temperature regulation center sensitively captures this change, and mistakenly believes that the body temperature rises, thereby initiating the body temperature regulation reaction to dissipate heat.
Through this principle, Bruno Conti and others established a mouse model with a hypothermia of 0.3-0.6 ° C lower than that of normal mice, and finally found that mice with low body temperature have a longer life expectancy than normal. Male mice with low body temperature have an average lifespan of 89 days longer than normal male mice and 112 days longer for females. To know that for mice with an average lifespan of only 2-3 years, this 100 days is equivalent to an extension of one-tenth of the lifespan, and the only change in body temperature is less than 1 °C.
The higher the body temperature, the faster the time passes.
This experimental conclusion, like the theory of relativity, was published in the Journal of Experimental Psychology as early as 1995. In the article, John Weldon and others from the University of Keele in the United Kingdom studied the ability to perceive time in the context of changes in body temperature between 1927 and 1993.
They allowed subjects in different body temperature conditions to record “they think” for 100 seconds on a stopwatch, and found that subjective time changes were inversely related to changes in body temperature, ie, when the body temperature was above 37 °C, the subjects The time that is often felt is faster (the subjective time is shorter); when the body temperature is lower than 37 °C, the opposite is true (the subjective time becomes longer). The researchers speculate that it is likely that high temperatures have caused the release of certain hormones, leading to more exciting nerve transduction.