Medical experts redefine normal human body temperature ranges

The long-held belief that 36.6 degrees Celsius is the universal standard for normal human body temperature is being re-evaluated by doctors and scientists. While the 36.6-degree norm originated from 19th-century observations, modern research suggests that healthy body temperature fluctuates within a much broader range.

Factors influencing temperature include age, time of day, physical activity levels, hydration, and menstrual cycles. For instance, temperatures are typically lower in the morning and higher in the evening. For healthy adults, a normal range is generally considered to be between 36.1 and 37.2 degrees Celsius, though some sources cite 35.9 to 37 degrees Celsius.

Age and measurement methods also play critical roles. Older individuals may have lower baseline temperatures, while children exhibit wider normal ranges. Additionally, results vary depending on whether the temperature is measured orally, under the arm, in the ear, or rectally. Scientists have also noted that average body temperatures in certain populations appear lower today than they were when the original 19th-century standards were established.