Study Reveals that the Average Body Temperature Is No Longer 98.6 Degrees
Think the conventional wisdom of 98.6 degrees Fahrenheit as the standard body temperature still holds true? Recent findings from Stanford Medicine researchers suggest otherwise. Their study reveals that individual body temperatures vary significantly, influenced by factors such as gender, age, weight, and height, with fluctuations occurring throughout the day.
Julie Parsonnet, MD, a professor at Stanford, underlines this variability, stating, “Contrary to common belief, the notion of a universal ‘normal’ temperature of 98.6 degrees Fahrenheit doesn’t apply to everyone. What’s considered normal depends on the individual and the circumstances, and it’s rarely as high as 98.6 degrees Fahrenheit.” Dr. Parsonnet authored the study, published in JAMA Internal Medicine on September 5.
Over the past century, the average body temperature of the typical American has declined by 0.05 degrees Fahrenheit per decade, attributed to improved living conditions that reduce inflammation. As a result, today’s average body temperature for most people is closer to 97.9 degrees Fahrenheit, rather than the long-held 98.6 degrees Fahrenheit.
The 98.6-degree benchmark originates from data collected in 1868 by a German doctor who studied approximately 25,000 individuals. His research revealed a range of temperatures, with men and older adults showing lower readings compared to women and younger adults. Temperatures also tended to peak in the afternoon, but the reported average remained at 98.6 degrees Fahrenheit.
Looking ahead, Dr. Parsonnet expressed her interest in further investigations into personalized definitions of fever and whether consistently higher or lower normal temperatures have implications for life expectancy.
Regarding fever classification, a medically significant fever is generally defined as a temperature exceeding 100.4º F. It’s important to note that not all fevers require fever-reducing medication, particularly if the individual is sleeping and eating reasonably well.
For adults, fever thresholds are as follows:
– At least 100.4 degrees Fahrenheit is considered a fever.
– Above 103.1 degrees Fahrenheit is categorized as a high fever.
– Above 105.8 degrees Fahrenheit is labeled as a very high fever.
In newborns, the average body temperature is around 99.5 degrees Fahrenheit, and a temperature above 100.4º F is regarded as a fever. In children, the average body temperature hovers at approximately 97.52 degrees Fahrenheit, with a fever defined as a temperature exceeding 100.4 degrees Fahrenheit. If an infant is younger than 3 months old and experiences a fever over 100.4º F or if any child exhibits a fever reaching 104º F or has a history of febrile seizures, it’s advisable to seek guidance from a pediatrician.