The average temperature of the human body has decreased in the last 150 years

for a Long time it was believed that the normal human body temperature is 37 DEGC (no wonder mercury medical thermometers this level highlighted in red).

This gold standard was established in 1851, a German doctor and Explorer Carl Reinhold August Wunderlich, conducting millions of measurements of tens of thousands of patients.

However, a tool which Wunderlich used to define ranges of “healthy” and “unhealthy” temperature was ultramodern for its time, but not for ours.

in addition, in the XIX century there was evidence that the body temperature of a person varies depending on hormones, metabolism, stress, and other factors.

In this regard, many researchers and clinicians of our time believed that the so-called index Wunderlich is not the standard.

it Turned out that it is. But the reason lies not in the imperfection of instruments or lack of knowledge of doctors of the last century.

In the new work, scientists from Medical school of Stanford University came to the conclusion that the measurement times Wunderlich reflect the actual historical pattern and, most likely, have significant errors. However, figure 37 DEGC can not be called gold standard of body temperature for modern people.

the Authors analyzed three sets of data.

In the earliest data are included nearly 24 million veterans of the Union army. Medical records were collected in the period between 1862 and 1930.

the Second set contained the data of more than 15 thousand people gathered in the framework of the national programme for investigation of the health of the U.S. population from 1971 to 1975.

the Third dataset was formed by experts of Stanford University in the period from 2007 to 2017. The sample size was more than 150 thousand people.

the Total number of temperature measurements of the three datasets was more than 677 thousand.

by Examining these indicators, the experts formed a picture of change the average rateerature the human body.

the Analysis confirmed many previous observations. Thus, the authors concluded that body temperature in young people, the women and larger people a little higher than the “average hospital”. In addition, it was confirmed that this figure rises in the evening.

But at the same time, the researchers found some differences in people who lived in different times.

In particular, the body temperature of men born in 2000-ies, on average by 0.59 DEGC lower than that of men born in the early 1800-ies. And the body temperature of women born in 2000-ies, 0.32 DEGC lower than that of women born in 1890-ies.

According to the authors ‘ calculations, the average human body temperature decreased by 0.03 DEGC per decade (this figure was derived taking into account the age, height and weight of people as well as the time of day at which measurements were conducted).

Experts ruled out the theory about the inaccuracy of the thermometers of the nineteenth century, as the trend persisted for the duration of time that encompasses the study (that is, the average gradually decreased for more than 150 years regardless of the advancement of thermometers).

the authors of the articles presented in the journal eLife, it is believed that the detected physiological change can be attributed to several factors.

first, the General state of health significantly improved over time thanks to progress in medicine (the development of antibiotics and vaccines to reduce the burden of chronic diseases and so on), as well as the emergence of new means of hygiene, availability of diverse foods and increasing living standards.

All of this has contributed to the overall reduction of the risk of occurrence of inflammatory processes. And if you have inflammation our body produces many specialized proteins (e.g., cytokines) that accelerate the metabolism and raise the body temperature.

second, the role played by other “benefits of civilization” – system heattion and air conditioning facilities. Thanks to them, the temperature of air changes in houses in cold and hot seasons slightly. So, the body does not need to expend additional energy for thermoregulation.

as for the new gold standard for human body temperature, according to the researchers, it is not easy to install. Because this indicator is influenced by many factors, including volatile.

by the Way, earlier researchers found that the increase in body temperature eliminates the depression.

Also “Conduct.Science” ( talked about the recently opened disease in which the body temperature of a person rises to 41 DEGC every few weeks.

Text: To.Science