The average body temperature is not 98.6 degrees.

In 1851, German physician Carl Wunderlich conducted a thorough experiment to determine the average human body temperature. In the city of Leipzig, Wunderlich stuck a foot-long thermometer inside 25,000 different human armpits, and discovered temperatures ranging from 97.2 to 99.5 degrees Fahrenheit. The average of those temperatures was the well-known 98.6 degrees — aka the number you hoped to convincingly exceed when you were too “sick” to go to school as a kid. For more than a century, physicians as well as parents have stuck with that number, but in the past few decades, experts have started questioningif 98.6 degrees is really the benchmark for a healthy internal human temperature. 

For one thing, many factors can impact a person’s temperature. The time of day, where the temperature was taken (skin, mouth, etc.), if the person ate recently, their age, their height, and their weight can all impact the mercury. Furthermore, Wunderlich’s equipment and calibrations might not pass scientific scrutiny today. Plus, some experts think humans are getting a little colder, possibly because of our overall healthier lives. Access to anti-inflammatory medication, better care for infections, and even better dental care may help keep our body temperatures lower than those of our 19th-century ancestors. 

In 1992, the first study to question Wunderlich’s findings found a baseline body temperature closer to 98.2 degrees. A 2023 study refined that further and arrived at around 97.9 degrees (though oral measurements were as low as 97.5). However, the truth is that body temperature is not a one-size-fits-all situation. For the best results, try to determine your own baseline body temperature and work with that. We’re sure Wunderlich won’t mind.