Normal Body Temperature Is Not Always 98.6
Over the years, I have noticed that my temperature is often colder than “anticipated.” On a typical day, it might be 97; if I have chills and other obvious symptoms of fever, I don’t have to have more than 100 of them. Strange, right? But other people tell me they had the same experience.
It turns out that body temperature is not so predictable. The idea that the norm is 98.6 comes from a German doctor who documented normal body temperature fluctuations over a century ago and noted that the average temperature is usually around 37 degrees Celsius. (This equates to 98.6 Fahrenheit.)
Nevertheless, he knew that the temperature range is considered the norm, and not a specific point on the thermometer. Our bodies are coolest in the wee hours of the morning, and we warm up during the day, peaking in the evening. In addition, activity can change our temperature: for example, we get hotter when we exercise.
If you have a menstrual cycle, your body temperature also changes throughout the month. After ovulation, your temperature will be about half a degree higher than in the two weeks or so before ovulation. When you start your period, your temperature will drop again.
What does it mean for fever
None of this really matters until you try to figure out if you or your child has a fever. For infants, it is recommended to call a doctor if a child under three months of age has a rectal temperature of 100.4. (Rectal temperatures are the most reliable for babies, and they can’t hold a thermometer under their tongue yet.) For older children, ask your doctor, but there may be no specific limit.
Temperature readings differ depending on where you take the measurement. The rectal temperature will be slightly higher than the oral (mouth) reading, and the axillary (axillary) temperature will be slightly lower.
While we know that the normal variation does not always correspond to this number of 98.6, it turns out that the normal temperature of people seems to have decreased over time since this number was established. A new study found that the current average is greater than 97.5 degrees .
What is the difference? Perhaps our modern life has somehow changed our bodies – for example, we have become taller. It could also happen that the “healthy” patients in the original studies were not as healthy as they looked. They may have had chronic infections or other health problems that caused them to have a fever, researcher Julie Parsonnet told the Wall Street Journal.
In any case, 98.6 has never been a hard and fast rule and enjoys less support than it used to. So if you feel like you’re always running slightly below the textbook average, that might be perfectly fine.