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Average human body temperature mysteriously declined, finds study
A new study seeks to understand why the average body temperature is no longer 98.6 degrees Fahrenheit.
- Average human body temperatures have declined, show several studies.
- A new paper looked at an indigenous population in the Amazon over 16 years.
- They found the new body temperature of the observed people to be 97.7°F, not the standard 98.6°F.
Temperature checks have become part of the new normal in the world under Covid, but the average body temperature may not be what the thermometers say. A series of studies, including a new paper, propose that the average human body temperature has been dropping for decades and is currently much lower than the accepted 98.6 degrees Fahrenheit, in fact, closer to 97.5°F.
The established standard for how warm your body should be came from the 19th century German physician Carl Wunderlich, whose 1851 measurement of 98.6°F set the bar for a long time. A 2017 study, however, that looked at 35,000 UK adults, found 97.9°F to be the average. A 2019 study measured 97.5°F as the normal temperature for Americans in Palo Alto, California.
Now, a team of physicians looked at the temperatures of the Tsimane, an indigenous people of the Bolivian Amazon, and discovered a comparable decrease. Observations over a 16-year-period revealed that the temperatures of the Tsimane went down about 0.09°F per year. Today, they are at about 97.7°F.
Michael Gurven, professor of anthropology from UC Santa Barbara, who led the research, commented that "in less than two decades we're seeing about the same level of decline as that observed in the U.S. over approximately two centuries."
The large study involved 18,000 observations of 5,500 adults and adjusted for factors that could have affected the body heat like outside temperature or body mass. They also used the same type of thermometer throughout, to make sure the instrument wasn't the issue.
Adjusting for various factors, they sought to figure out the reason for the decrease which was consistently noticed. They conjectured that fewer infections as a result of better hygiene, cleaner conditions, vaccinations, and improved medical treatments were possibly responsible for their find.
While such possibilities are there, they did not account fully for the observations. Chances are, a combination of influences is responsible for the lower temps. "Declines might be due to the rise of modern health care and lower rates of lingering mild infections now as compared to the past," Gurven shared. "But while health has generally improved over the past two decades, infections are still widespread in rural Bolivia. Our results suggest that reduced infection alone can't explain the observed body temperature declines."
Some additional explanations offered by Gurven include the fact that we now have better anti-inflammatory drugs and even the advancements in air conditioning.
"While Tsimane body temperatures do change with time of year and weather patterns, the Tsimane still do not use any advanced technology for helping to regulate their body temperature," Gurven explained. "They do, however, have more access to clothes and blankets."
It should be noted that the study looked at average temperatures, and physicians do not think there is truly one temperature that everyone should have. What's considered "normal" is really a range of temperatures that depends on the individual. Still, the information is valuable in pointing to the population's overall health.
Check out the new paper in Sciences Advances.
- Psychogenic shivers: why we get the chills when we aren't cold ... ›
- It's cold! A physiologist explains how to keep your body feeling warm ›
What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
With just a few strategical tweaks, the Nazis could have won one of World War II's most decisive battles.
- The Battle of Britain is widely recognized as one of the most significant battles that occurred during World War II. It marked the first major victory of the Allied forces and shifted the tide of the war.
- Historians, however, have long debated the deciding factor in the British victory and German defeat.
- A new mathematical model took into account numerous alternative tactics that the German's could have made and found that just two tweaks stood between them and victory over Britain.
Two strategic blunders<p>Now, historians and mathematicians from York St. John University have collaborated to produce <a href="http://www-users.york.ac.uk/~nm15/bootstrapBoB%20AAMS.docx" target="_blank">a statistical model (docx download)</a> capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different. </p><p>Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.</p><p>"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a <a href="https://www.york.ac.uk/news-and-events/news/2020/research/mathematicians-battle-britain-what-if-scenarios/" target="_blank">statement</a>. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.</p><p>"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."</p><p>Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.</p><p>Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.</p>
A tool for understanding history<p>This technique, said co-author Niall Mackay, "demonstrates just how finely-balanced the outcomes of some of the biggest moments of history were. Even when we use the actual days' events of the battle, make a small change of timing or emphasis to the arrangement of those days and things might have turned out very differently."</p><p>The researchers also claimed that their technique could be applied to other uncertain historical events. "Weighted bootstrapping can provide a natural and intuitive tool for historians to investigate unrealized possibilities, informing historical controversies and debates," said Mackay.</p><p>Using this technique, researchers can evaluate other what-ifs and gain insight into how differently influential events could have turned out if only the slightest things had changed. For now, at least, we can all be thankful that Hitler underestimated Britain's grit.</p>
We’ve mapped a million previously undiscovered galaxies beyond the Milky Way. Take the virtual tour here.
See the most detailed survey of the southern sky ever carried out using radio waves.
Astronomers have mapped about a million previously undiscovered galaxies beyond the Milky Way, in the most detailed survey of the southern sky ever carried out using radio waves.
A new study shows our planet is much closer to the supermassive black hole at the galaxy's center than previously estimated.
Credit: NAOJ<p><em>Arrows on this map show position and velocity data for the 224 objects utilized to model the Milky Way Galaxy. The solid black lines point to the positions of the spiral arms of the Galaxy. Colors reflect groups of objects that are part of the same arm, while the background is a simulation image.</em></p>
Apple sold its first iPod in 2001, and six years later it introduced the iPhone, which ushered in a new era of personal technology.