36.5°C instead of 37°C: why your normal body temperature is actually lower

Think your normal body temperature should be 37°C on the dot? Well, you might want to sit down (but not too close to a radiator). That number, so embedded in our checkups and childhood memories of looking suspiciously at the family thermometer, is in fact outdated. Yes, for real. Science has known this for about two decades, but public perception is still stuck somewhere in the 19th century. Let’s clear the air (and maybe break a mild sweat), and get to the bottom of what our average temperature really is, and how the 37°C myth keeps hanging on.

The Persistent 37°C Myth — And Where It Came From

The idea that 37°C is the universal standard for body temperature has clung on much longer than shoulder pads or pet rocks ever did. Most people, when fever strikes or curiosity bites, still look for that number as a benchmark.

But where did it even come from? The roots of this number trace back to the 1870s, when a doctor working in a German clinic decided to be the thermometer authority. After measuring the temperature of 25,000 people (talk about dedication!), he concluded that 37°C was the average. This figure, once etched into medical textbooks, gradually made its way into medicine cabinets and the collective psyche.

However, in the early 1990s, Philip Mackowiak, emeritus professor at the University of Maryland’s School of Medicine, started poking holes in this so-called standard. He questioned whether thermometers from that era were trustworthy enough to anchor such a major health indicator, and suspected that maybe—just maybe—the foundation of our 37°C normal was shaky from the start.

The Reality Check: What’s Our Real Average Body Temperature?

Surprise: Your average body temperature is actually lower—closer to 36.5°C. Multiple scientific studies have dug into this, and the results are clear. Turns out, the “37” we all grew up with just isn’t correct anymore. In fact, it might never have been strictly accurate to begin with.

Recent research makes things even more interesting. A 2017 study by five Stanford University scientists swept up more than 600,000 temperature readings collected between 1862 and 2017. What they found was striking: the average human body temperature has gradually dropped by about 0.03°C every decade, arriving at today’s standard of 36.5°C. So, if you’ve ever felt a tiny bit cooler than your grandma claimed was healthy, you now have 150 years of data backing you up.

But the plot thickens! Another study published in 2020, led by anthropologist Michael Gurven from the University of California, confirmed this trend. His team studied the Tsimane (also called Chimane) people, subsistence farmers and hunters living in relative isolation in Bolivia. Their conclusions? The same. Human bodies are cooling down, no matter the geography or lifestyle.

Why Are We Cooler Than Before?

Now, scientists don’t all agree on exactly why our bodies are cooling off, but they have some solid hypotheses. The Stanford team links this change to evolving lifestyles and environments. To quote Julie Parsonnet, one of the authors: “The environment in which we live has changed, including the temperature in our homes, our contact with microorganisms, and the food we have access to.” In other words, the modern comforts and advancements we enjoy may be helping to turn down our internal thermostat.

The University of California researchers offer a similarly varied list, with possible culprits including:

• Air conditioning
• Changes in diet
• Chronic diseases
• Immune system activity
• Dental health issues
• Parasites
• Sleep habits
• Anti-inflammatory medications

So, it’s a whole cast of modern influences conspiring to leave us a little chillier than our great-great-grandparents were.

Measuring Up: What Counts as “Normal” Today?

Before you panic the next time your thermometer reads 37°C, let’s put things in perspective. According to current findings, temperatures from 35.7°C to 37.3°C are all fair game for being considered “normal.” So, hitting 37°C doesn’t automatically mean fever—just that you’re comfortably inside the modern average. (Whew!)

The numbers may change, but what matters most is how you feel. If you’re unwell and concerned, call a doctor. But if you just want a reason to show off your science knowledge, now you’ve got a fresh one. Next time someone insists only 37°C will do, you can educate them with the finest 21st-century data—temperature drama included, no extra charge.

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David Miller

David Miller is an entertainment expert with a passion for film, music, and series. With eight years in cultural criticism, he takes you behind the scenes of productions and studios. His energetic style guides you to the next big releases and trending sensations.