Today the temperature of the body is about 37°C is considered normal. However, the normal temperature of the human body can fluctuate by a few degrees. Factors such as age, environment, weight, height, gender and even time of day play a role in the readings of the thermometer. But what is the body temperature was considered normal in the past? According to a study published in the open access journal eLife, the body temperature of the person is lower today than two centuries ago. The authors argue that since 1851 — it was then collected the first systematic record of the temperature of the human body gradually began to decline.
What temperature is considered normal?
The gold standard of temperature of 36.6°C is based on the work of the German doctor Carl Reinhold August Wunderlich, which in 1851 made the first data from 25 000 patients and averaged them. Researchers from the Medical school of Stanford University has carefully studied the old and new data on human body temperature to find out whether it is possible to explain the differences of equipment and techniques that were used in the past.
The study team compared the temperature from a number of sources, Dating from 1862-2017 years. In General, the researchers analyzed the rates of more than 677 000 subjects. Based on the testimony, they found that the average temperature in men fell about to 36.3°C. the Average temperature in women also declined,not as much, about to 36.6°C. Thus, the scientists were able to document that since the mid-19th century the human body temperature is steadily reduced.
Moreover, researchers have confirmed some early insights Wunderlich, including that the body temperature of young men at rest is higher than in adults, a body temperature of women slightly higher than men. Taking into account the method of measurement of temperature, as well as all the known data about the used tools, the researchers came to the conclusion that our bodies are really cool. But why?
Why the body temperature of the person is lower today than 160 years ago?
Despite the fact that the definition of the reason we suck is beyond the scope of the study, the authors suggested several possible explanations. When Dr. Wunderlich conducted measurements, the average life expectancy was just 38 years old, and the body temperature reached an average of 36.9°C. moreover, in those years were spread chronic infections, from tuberculosis to syphilis. Since the average body temperature usually decreases with age and increases with the presence of infection, could it happen that young people suffered from chronic diseases and therefore, their bodies were hot.