Nov 2, 2026 04:08 PM
(This post was last modified: Nov 2, 2026 04:09 PM by C C.)
https://ca.news.yahoo.com/scientists-thi...00230.html
EXCERPTS: From this vast dataset Wunderlich calculated an average, 37C (98.6F), for healthy adults. This became the benchmark for tracking normal human body temperature. If that rose above 38C (100.4F), it signalled fever, he wrote.
[...] Yet the average individual today has also now been shown to be cooler than their counterpart 150 years ago, with American men running about 0.59C lower than in the early 19th-Century.
A decade ago, Parsonnet's team analysed three large datasets involving multiple temperature readings from nearly 190,000 people in the United States, taken between 1862 and 2017. "The new normal [for adults] seems closer to 97.5F (36.39C)," she says. Numerous studies, both before and since, echo Parsonnet's findings.
[...] A handful of explanations could explain the lower averages we see today. Parsonnet, for instance, believes, they are the result of healthier overall populations. In Wunderlich's day, life expectancy was 38 years. Today, it's nearly double that.
"People didn't live the healthy lives that we live now," says Parsonnet. "They [often] had lots of things wrong with them – tuberculosis, terrible dental care, dysentery, rheumatic fever, and osteomyelitis."
"When your immune system is trying to defend you against all these things that are trying to kill you, it consumes calories. And calories are another word for heat," Parsonnet says.
[...] Mackowiak, however, thinks the fall in average body temperature might be due to something else entirely.
When he had the chance to examine one of Wunderlich's glass thermometers in person, Mackowiak told me he noticed that it was calibrated roughly 2C higher than modern thermometers. This means that any readings made via these instruments would be 2C warmer than they should have been. Back then, measuring temperatures were a cumbersome affair, says Mackowiak.
[...] In other words, Wunderlich's figure might have been flawed to begin with. He also took armpit temperatures, rather than the oral readings that are more common today – making his measurements tricky to compare to modern ones.
[...] Does all this mean it's time to rethink the special significance accorded to 37C (98.6F)? Some already have, including two authoritative sources widely used by physicians... (MORE - missing details)
EXCERPTS: From this vast dataset Wunderlich calculated an average, 37C (98.6F), for healthy adults. This became the benchmark for tracking normal human body temperature. If that rose above 38C (100.4F), it signalled fever, he wrote.
[...] Yet the average individual today has also now been shown to be cooler than their counterpart 150 years ago, with American men running about 0.59C lower than in the early 19th-Century.
A decade ago, Parsonnet's team analysed three large datasets involving multiple temperature readings from nearly 190,000 people in the United States, taken between 1862 and 2017. "The new normal [for adults] seems closer to 97.5F (36.39C)," she says. Numerous studies, both before and since, echo Parsonnet's findings.
[...] A handful of explanations could explain the lower averages we see today. Parsonnet, for instance, believes, they are the result of healthier overall populations. In Wunderlich's day, life expectancy was 38 years. Today, it's nearly double that.
"People didn't live the healthy lives that we live now," says Parsonnet. "They [often] had lots of things wrong with them – tuberculosis, terrible dental care, dysentery, rheumatic fever, and osteomyelitis."
"When your immune system is trying to defend you against all these things that are trying to kill you, it consumes calories. And calories are another word for heat," Parsonnet says.
[...] Mackowiak, however, thinks the fall in average body temperature might be due to something else entirely.
When he had the chance to examine one of Wunderlich's glass thermometers in person, Mackowiak told me he noticed that it was calibrated roughly 2C higher than modern thermometers. This means that any readings made via these instruments would be 2C warmer than they should have been. Back then, measuring temperatures were a cumbersome affair, says Mackowiak.
[...] In other words, Wunderlich's figure might have been flawed to begin with. He also took armpit temperatures, rather than the oral readings that are more common today – making his measurements tricky to compare to modern ones.
[...] Does all this mean it's time to rethink the special significance accorded to 37C (98.6F)? Some already have, including two authoritative sources widely used by physicians... (MORE - missing details)