For more than a century, we have taken the landmark 37 degrees C or 98.6 degrees F as a marker for human health. You know it’s a body temperature of a normal healthy person. Above 37 degrees C means your body is having a fever, and below 37 degrees C means your body temperature is falling, which can be as dangerous as life.
But Julie Parsonnet, a medical researcher at Stanford University, USA said: “Our body temperature is not the same as what people think. What people learn when they grow up is that our body’s normal temperature is 98.6 degrees Fahrenheit [hay 37 độ C], is wrong“.
The human body is cooling, the body temperature is no longer 37 degrees Celsius
Errors in thermometers more than 100 years ago
In fact, 37 degrees Celsius has been the German doctor Carl Reinhold August Wunderlich made since 1851. At that time, with a 22 cm long thermometer, Wunderlich made millions of body temperature measurements on Tens of thousands of patients to take out the average figure.
“In the 19th century, thermometers were just invented“Parsonnet noted. Wunderlich’s most advanced equipment by that time has now become obsolete.
In fact, Wunderlich’s thermometer took 15 minutes to produce a result. In total, he measured the temperature of 25,000 people, requiring up to 250,000 hours, equivalent to 10,000 days.
Dr. Philip Mackowiak, a medical professor at the University of Maryland Medical College, discovered that thermometers from 100 years ago might have errors within the range of 1.5 degrees Celsius compared to current thermometers.
So he and his colleagues did a study to re-examine human body temperature. Professor Mackowiak found that all of our body temperature fluctuated between 6 am and 6 pm and was not fixed in a single number.
And women often have higher body temperatures than men. The average body temperature is 98.4 degrees Fahrenheit (36.89 degrees Celsius) compared to 98.1 degrees Fahrenheit (36.72 degrees Celsius) for men, both lower than 98.6 degrees Celsius. F (37 degrees C) of Wunderlich.
In addition, body temperature seems to change with age. A 2005 study found that the temperatures of 150 seniors reached 97.3 degrees Fahrenheit (36.28 degrees Celsius) in the early morning and 97.8 degrees Fahrenheit (36.56 degrees Celsius) before they went to bed.
Thermometers 100 years ago have a difference of 1.5 degrees Celsius compared to modern thermometers.
The human body is actually cooling by 0.03 degrees Celsius per decade
Parsonnet and her colleagues at Stanford University were curious about these new results. They wondered whether the difference was really due to the fact that the thermometers were colder now than they were 100 years ago. Or is the human body really cooling?
To find out, Parsonnet searched the medical records of nearly 24,000 veterans of soldiers who had participated in the US Civil War. She searched for medical records of their body temperature.
These figures were then compared to about 15,000 records from a medical survey in the early 1970s in the US and 150,000 records since 2000 in Stanford’s clinical data platform. In total, Parsonnet’s team has detailed information on over half a million independent body temperature measurements.
As a result, they found a clear and significant difference over time. The body temperature of people living in the late 19th century is a little warmer than us. For example, boys born from 2000 onwards are 0.59 degrees cooler than their cavalry, who were born in the early 1800s.
On average, every decade, a person’s body temperature has decreased by 0.03 degrees Celsius. The same decline has been observed in women, with a decrease of 0.32 degrees Celsius since the 1890s.
“Physiologically, people today are certainly different from people in the past“, Parsonnet explained.”The environment we live in has changed, including our indoor temperature, our exposure to microorganisms and the food we have access to.
All of this means that, although we think we humans are single and have not changed in the flow of evolution, we of the past and the present are not exactly the same. We are really changing physiologically. “
Improvements in health and nutrition may be another explanation. Our body mass is increasing, it will push the warmer metabolites. In contrast, better health means that our bodies today have fewer infections, which makes us less likely to have a fever and lower average body temperature.
Carl Reinhold August Wunderlich, the first person to calculate the human body temperature.
Clearly, human body temperatures are changing. And these changes compared to the past can give us insight to predict future changes, as we enter a more drastically changing world, both socially and socially. school.
A future, when the Earth warms up can make our body temperature rise a little bit. In particular, accompanied by many new diseases and declining health can make our fever frequency greater.
In short, our body temperature has never been fixed at 37 degrees Celsius. Wunderlich’s magic figure has existed for nearly 200 years, now, it must be slightly adjusted.
But underneath the golden spring, perhaps Wunderlich could also smile when he learned that it was not entirely because his millions of meticulous measurements in the past were faulty, but simply the body of his descendants. cools down.
The new research has been published in eLife.
Refer Sciencealert, Latimes