Chill, man. Chill.

Normal body temperature is 98.6 deg Fahrenheit, right?

The 98.6 standard was set in the late 1800s based on observations of many patients by attending physicians. So it is an average observation, not a clinically established standard. We actually have no idea what average human body temperatures were prior to about 1860. But we do know this, it has been slowly decreasing.

Based on over half a million observations through 2017, average body temperature for a healthy person is now 97.9 deg F.

Dr. Julie Parsonette at Standford University Medical School offers several possible explanations for the slow decline. Chronic inflammation has decreased over the last 200 years, while general overall heath has improved. Better indoor heating and cooling systems make it easier for the body to maintain and regulate its internal temperature.

Body temperature depends on weight, gender, age and time of day. What defines a fever may need to be reassessed, especially for old guys like me, who tend to run a bit cooler than our younger brethren. See? Old is cool!