Stanford researchers find average human body temperature is declining

Scientific research indicates that the average human body temperature has gradually decreased over the last 150 years. While 37 degrees Celsius was established as the medical standard in the 19th century by German physician Carl Wunderlich, modern data suggests the actual average for healthy adults is now closer to 36.39 degrees Celsius.

A team of scientists from Stanford University analyzed extensive datasets involving nearly 190,000 individuals in the United States, covering records from 1862 to 2017. Their findings show that the average temperature for American men has dropped by approximately 0.59 degrees Celsius compared to the early 19th century. Similar trends have been observed in other populations, such as the Tsimane community in the Bolivian Amazon.

Researchers suggest several factors for this decline. Improved public health, better hygiene, and advancements in medicine mean that modern immune systems do not have to work as hard to fight chronic infections, which previously generated significant metabolic heat. Additionally, controlled indoor environments through heating and air conditioning may reduce the body's need to expend energy to maintain its core temperature.