The “New Normal” for Body Temperature



All our lives we’ve considered 98.6º to be the normal body temperature. This number was calculated by a German physician in the mid-1800s, based on an average of the temperatures of 25,000 patients. However, if you’re healthy and have seen a doctor lately, chances are you were told your temperature was less than 98.6º. There are several newer studies that indicate that body temperature has decreased over time. Now, a more accurate number is in the 97.5º to 97.7º range. The question is, why? In the mid-1800s, life expectancy was quite short, and many people had untreated infections like gum disease and tuberculosis that could have caused persistent fevers. In addition, the temperature was normally taken under the arm rather than by mouth, and thermometers were probably not as accurate as those made today. Better health care and increased use of anti-inflammatory drugs like aspirin and ibuprofen are part of the reason the number has been lowered. While news that the normal body temperature may be drifting down over time is intriguing, it's not cause for alarm — and it doesn’t mean the definition of fever should change. That remains at 100.4º to indicate a fever and 103.1º to indicate a high fever. Scientists now believe it's probably time to abandon the assumption that 98.6º is a normal temperature, as something around 97.5º is more accurate.