Is 37C really your normal body temperature?

That 37C everyone quotes is a 150-year-old figure, and your real normal is probably a little lower.

Normal body temperature is a range, not a single magic number. The classic 37C (98.6F) came from a German doctor in the mid-1800s, measuring under the armpit with the instruments of his day. Big modern studies put the healthy average closer to 36.6C, and it shifts through the day - lowest in the early morning, highest in late afternoon - while also varying by age, sex and where you measure. The average has even crept downward over the last century, partly because our bodies genuinely run a touch cooler now, not just because old thermometers read high.

Your thermometer reads 36.5C in the morning and you panic that you are sick, but that is just your normal low point, not a problem.

Think of normal body temperature as a band of roughly 36.1 to 37.2C, not a fixed 37C, and judge a fever against your own baseline.

Knowing your true baseline means you spot a real fever faster and stop worrying over a reading that is perfectly normal.

37C is the famous round number; your real normal hides just under it.

Learn the idea and practice English at the same time.