A recent study from Stanford University challenges the commonly held idea that the normal body temperature is 37 degrees Celsius.
- Work by German physician Carl Reinhold August Wunderlich carried out in 1868 established the normal body temperature at 37 degrees. A new study calls these data into question.
- For adults, it is between 36.27 to 36.7 degrees, with an overall average of 36.6 degrees.
- It also varies depending on several factors. The main ones, according to researchers, are age, gender, weight and time.
The “so-called normal” body temperature of 37 degrees is not that universal. It varies depending on several factors, such as age, gender, weight and even the time of day, according to a study by Stanford University.
Body temperature: several factors taken into account
The norm of a “normal” body temperature of 37 degrees was established in 1868 by the work of the German doctor Carl Reinhold August Wunderlich. To verify the veracity of this data, Stanford researchers Medicine analyzed more than 600,000 oral temperature measurements taken from patients at the Stanford center Health Care between 2008 and 2017. They also recorded the time they were taken, as well as the participants’ age, gender, weight, height, body mass index, medications and health status. The analysis found that adults have normal temperatures ranging from 36.27 to 36.7 degrees, with an overall average of 36.6 degrees, not the expected 37 degrees. Furthermore, they vary according to 4 characteristics: age, sex, weight or even the time of day.
For example, men tended to have lower temperatures than women. In addition, they decrease with age and size. On the other hand, they increase with weight. “The most influential factor, however, was the time of day, with temperatures cooler early in the morning and warmer around 4 p.m.”specify the authors in a communicated.
Age, gender, weight and time account for a quarter of the variability
Researchers estimate that age, sex, weight and time of day account for a quarter of the variability in normal body temperatures. On the other hand, they specify that other elements that they did not take into account in their study can also influence it.
Among these factors, they cite clothing, physical activity, the menstrual cycle, the weather, and even the consumption of hot or cold drinks. Therefore, it is important to be aware of this risk of variability when measuring body temperature and interpreting the results.
A temperature individualized approach could improve the management of patients
This study shows that it would be interesting to have individualized benchmarks for patients’ body temperature. This would allow better support. To illustrate this point, Julie Parsonnetlead author of this study published in JAMA Internal Medicine on September 5, made from personal experience. Her mother-in-law, who had a serious heart infection, went undiagnosed for weeks because her temperature never reached a conventional fever (generally defined as above 37.7). For the expert, a personalized assessment of body temperature might have made it possible to detect the disease earlier.
Would you like to know your personalized body temperature? The researchers put online a website Web using the statistical model they have developed. It allows you to know the expected temperature of a person throughout the day based on their personal characteristics.
