98.6

Over the past few decades, evidence has been mounting that the average human body temperature is not really 98.6 degrees Fahrenheit. Instead, most people’s baseline is a little bit cooler.

The standard of 98.6 was established over 150 years ago by the German physician Dr. Carl Wunderlich, who reportedly took over a million measurements from 25,000 people. Temperatures ranged from 97.2 to 99.5, and the average was 98.6. Dr. Wunderlich also established 100.4 degrees as “probably febrile.”

However, a study published in September that evaluated the temperatures of more than 126,000 people between 2008 and 2017 found that the average is closer to 97.9 degrees. Other modern-day studies have reported similar numbers.