Why it is fine if your body temperature is slightly lower than 'normal'
98.6°F (37°C) is no longer normal average body temperature
Hello! How have you been so far in 2021? A little better this year, I hope.
I’m very excited that COVID-19: Separating Fact from Fiction is getting published in a few days! It is very gratifying to hear from the few people who have already seen early copies of the book. Someone in the media who has been covering COVID-19 for a year found the book detailed, and yet simple to understand. And that made my day, because because striking that balance is difficult.
I am also exceptionally grateful to those who reviewed the book during the writing process. Kevin Davies, one of my favorite popular-science authors (and author of Editing Humanity, one of my top-20 popular science books of 2020) had this to say about the book—
Here’s the link to the Kindle version on Amazon.com. Here’s the link to the hardcover version on Amazon’s Indian site.
While on the topic of COVID-19, I wrote a long essay for Mint on vaccine hesitancy and how India can fight it. This is a hot topic right now. This completes a trilogy of essays on COVID-19 vaccines that I've written for Mint. In May 2020, I wrote a long essay saying COVID-19 vaccines are coming. In November 2020, I wrote one saying the vaccines are here. Now, I highlight concerns people have with vaccines and why they might not be taking them.
Now on to the main topic of the newsletter.
Why 98.6°F (37°C) is no longer normal average body temperature
It's a fact everyone knows and is taught from school to medical college— a thermometer reading of 98.6°F (37°C) typically indicates the average "normal" body temperature. But like me, you may be puzzled because your own body temperature always registers lower. Well, it turns out that we are not abnormal. Like many things, the 98.6°F reading is no longer a valid standard.
To understand why, we have to go back to 1851 and the origin of the standard reading of human body temperature. That year, German physician Carl Reinhold August Wunderlich took millions of auxiliary (under-arm) temperatures from 25,000 patients in Leipzig, Germany and declared that the standard for normal human body temperature is 98.6°F.
But more recently, Stanford researchers have found that over 150 years there has been a steady cooling in body temperatures. This has been observed not only in the United States, but in other parts of the world. This isn’t just because of a difference in thermometers; this is an actual physiological difference that has happened over time. And the current average is 97.9°F.
So what is actually going on? Researchers in an article published in the scientific journal eLife think that we are probably seeing a population-level control of inflammation due to less infection, better sanitation, and standards of hygiene. Compared to even 100 years ago, fewer people have chronic infections these days. Due to advances in modern medicine and drug discovery, small pox has been eradicated. Other diseases like cholera and malaria are no longer the scourge they once were. TB is treatable.
What a lower average normal temperature indicates is that basal metabolic rates have also gone down. Across most animal species and even within species there is a relationship between metabolism and longevity. A higher metabolism is associated with a shorter lifespan. On the other hand, a lower metabolism can lead to weight gain.
So does a lower average normal temperature mean that the definition of fever is also going to change?
It’s not clear yet because even now there isn’t clear consensus of the temperature considered a “fever” right now.
Technically, the CDC defines a fever as having a temperature of 100.4 degrees or greater. However, the organization says that it also considers someone to have a fever when they “feel warm to the touch or give a history of feeling feverish.”
The Infectious Diseases Society of America also recognizes that fever detection isn’t totally clear-cut. The organization says you have a fever if you have a single oral temperature of more than 100 degrees Fahrenheit or two repeated oral temperatures above 99 degrees, a rectal temperature above 99.5 degrees, or an increase in your temperature of two degrees over your baseline.
Body temperature is such a fundamental aspect of normal health and of assessing illness, and we have been treating it like it is an immutable number. I can’t stop thinking about how this simple observation might be direct physiological evidence from our own bodies of how microbiology and modern medicine have improved human life.
What else I’m reading
Do mosquitoes get drunk?
Probably not. But there’s another interesting counter-question. Do drunk people get bitten more often? There’s a very preliminary study (that should be repeated) that claims they do.
Exactly why mosquitoes appear to be more attracted to drinkers, no one is quite sure. We do know mosquitoes home onto humans thanks to two chemicals we exhale when we breathe: carbon dioxide and octanol. (Octanol, a secondary alcohol created from the breakdown of linoleic acid, is also commonly known as “mushroom alcohol” because it’s the compound that helps give mushrooms their taste.)
Chili-powered solar panels
Capsaicin-laced solar panels are among the most efficient in the world. In case you were wondering, capsaicin is what makes chili peppers spicy.
Adding capsaicin expands the grains which make up the active material of the solar cell, allowing it to more effectively transport electricity. More importantly, the material goes from having a deficit of electrons to having an excess, which changes how the cell operates and allows more sunlight to be converted to electricity. In essence, adding capsaicin adds electrons (which may or may not be the same effect you experience on your tongue after a particularly spicy biryani).
A discovery to remember
A lot happened in 1971. Bangladesh became an independent nation.
It's the 50th anniversary of one of the greatest achievements in science- the discovery of an enzyme called reverse transcriptase (RT). RT changed our knowledge of cancer, helped us to understand HIV/AIDS in the 80s, and even set the stage for a reliable test for SARS-CoV-2. last year. Here’s an article that sums up the discovery of this remarkable enzyme.
Viruses in ice
Researchers went looking for the oldest ice on the planet. What they didn’t bargain on was finding 15,000 year-old-viruses including 28 types that had never before been identified.
They note that their work might grow in importance as the planet heats up due to global warming and melts glaciers, possibly unleashing deadly viruses.
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