Average human body temperature is no longer 36.6°C, says Standford study

For a century, we have thought that 36.6°C (98.6°F) was the average temperature of a healthy person. But turns out there is no such thing. A new study from Stanford University challenges this long-standing standard.
A study led by

Julie Parsonnet

, an expert in infectious diseases, found out that the commonly accepted average temperature of 36.6°C is incorrect.
Dr. Parsonnet and her team at Stanford University analyzed 618,306 oral temperature measurements from adult outpatients seen at Stanford Health Care from 2008 to 2017. Along with that, they also noted down the time of the day it was taken, and each patient’s age, sex, weight, height, body mass index, medications, and health conditions.
The findings were surprising because the normal human body temperatures they measured varied between 36.2°C and 36.8°C (97.3°F and 98.2°F). This study suggests that the commonly thought normal value is too high.

“Most people, including many doctors, still think that everyone’s normal temperature is 98.6 F. In fact, what’s normal depends on the person and the situation, and it’s rarely as high as 98.6 F,” Dr. Parsonnet said in a statement. The study is published in

JAMA Internal Medicine

.
The decrease in the average body temperature in the US could be because of the metabolic rate. The researchers noted that a population-wide decline in inflammation could have contributed to this reduction “Inflammation produces all sorts of proteins and cytokines that rev up your metabolism and raise your temperature,” Parsonnet added. Similarly, there has been a dramatic improvement in public health in the past 200 years, thanks to the advances in medical treatments, better hygiene, greater availability of food, and improved standards of living.

“Physiologically, we’re just different from what we were in the past. The environment that we’re living in has changed, including the temperature in our homes, our contact with microorganisms, and the food that we have access to. All these things mean that although we think of human beings as if we’re monomorphic and have been the same for all of human evolution, we’re not the same. We’re actually changing physiologically,” Parsonnet said.
(Pic courtesy: iStock)