For the past few years, I’ve found myself ranting about my family’s digital thermometers. Part of it is that my children think they are toys. They’ll find one in the medicine cabinet and then go sticking the thermometer up their nose, out the window, or next to the radiator to try increase their temp and coerce me into keeping them home from school.
But I’ve also just been convinced that thermometers these days are trash—and I’ve replaced quite a few thermometers because of how inaccurate they seem to me.
“I can’t possibly be only 97.3 degrees,” I’ll say to my family when I go and test one of our thermometers. “This damn thing is broken … again.”
“They don’t make these thermometers like they used to,” I’ll moan.
Only as it turns out, the joke is probably on me, because 97.3 degrees might just be my normal temperature — at least according to new research.
Yup, that’s right. You know that rule that we all grew up knowing, that 98.6 degrees Fahrenheit was the average temperature? Well, this might be yet another childhood norm that needs reevaluation.
It may be hard to believe, but researchers at Stanford University have concluded that the average human temperature has dropped over the past two centuries, and 98.6 degrees just isn’t accurate anymore. In fact, the temperature that I always seem to find when I test my digital thermometer might be right on the mark, because the average human temperature is more in the range of 97.5.
“Our temperature’s not what people think it is,” explained Julie Parsonnet, MD, one of the study researchers, in a press release. “What everybody grew up learning, which is that our normal temperature is 98.6, is wrong.”
In the study, published in eLife, Parsonnet, along with four other researchers, looked at human body temperature since the 1800s, when the whole 98.6 thing was set in stone by German physician Carl Reinhold August Wunderlich. Wunderlich published the magic number in an 1868 book, but it’s only recently that researchers have called the number into question.
After analyzing and compiling data from the past two centuries—from medical records of Civil War veterans, to U.S. National Health and Nutrition Examination Survey data from the 1970s, to data from the Stanford Translational Research Integrated Database Environment—the researchers concluded that body temperature has decreased about 0.03 degrees every decade for the past 157 years.
How freaking fascinating is that?
As for why the heck this is happening, the researchers aren’t exactly sure, but have some theories, mostly having to do with how modern life has changed the human body.
“Physiologically, we’re just different from what we were in the past,” Parsonnet explained.
Her theory has to do with the fact that we live in an age when we are able to control the temperature of our living environment more easily, and this may have changed our overall physiology over time.
“The environment that we’re living in has changed, including the temperature in our homes, our contact with microorganisms and the food that we have access to,” said Parsonnet. “All these things mean that although we think of human beings as if we’re monomorphic and have been the same for all of human evolution, we’re not the same. We’re actually changing physiologically.”
Another theory has to do with how much healthier we’ve become, thanks to advancements in modern medicine.
“Inflammation produces all sorts of proteins and cytokines that rev up your metabolism and raise your temperature,” Parsonnet explained, also pointing to improvements in public health, hygiene, and accessibility of food, and the overall standard of living.
Dr. Eric Ascher, family medicine physician at Lenox Hill Hospital, agrees with Parsonnet’s assessment that the drop in average body temperature means that humans are actually getting healthier.
“We’re living much healthier lifestyles now,” Ascher told CBS New York. “There’s an awareness on exercise, there’s an awareness on nutrition, and that is allowing our bodies not to work as hard to maintain a steady temperature. Accessibility of over-the-counter medications like ibuprofen, for example, is helping our bodies decrease inflammation, and when there’s less inflammation, there’s a lower body temperature.”
Awesome. But what about fevers? Does the standard for what constitutes a fever change now? This is definitely an important question for parents, whose kids catch every virus under in their first few years of life.
According to Ascher, at this time, we should just stick with the advice that 100.4 degrees and up is a fever. “Realistically, it’s not going to make too much of a difference with the body temperature being a couple of decimal places different,” he explained.
Regardless of the new temperature norms, Ascher says that we all have our own baseline temperatures and it’s good to know what that is for your child so you can understand what might be going on with their bodies when they are sick.
Obviously, I should add, if you have any questions about your child’s average body temperature or fever threshold in light of this new research, definitely ask your doctor for advice.
But basically, those of us who have been walking around complaining about our broken thermometers should just chill out and realize that getting a reading in the 97-ish range may just be our normal. Yay for colder (and maybe healthier) people!