What should your 'Normal Body Temperature be, and why?'

Summary

Podcast Summary: “What should your ‘Normal Body Temperature’ be, and why?”

Podcast: Who Smarted?
Date: January 16, 2026
Host/Narrator: Trusty (with Chet Nickerson and special appearance by “Dr. Carl Reinhold August Wunderlich”)

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Overview of Episode Theme

This episode of Who Smarted? sets out to answer questions about normal human body temperature—where the widely-quoted “98.6°F” number comes from, how accurate it is today, why body temperatures change, and how both people and animals regulate their temperatures. Using humor, puns, interactive questions, and a surprise “visit” from the ghost of Dr. Wunderlich, the episode breaks down science and history for young listeners while keeping things lively and funny.

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Key Discussion Points and Insights

1. What’s a “Normal” Body Temperature?

• Quiz Time: Listeners are first asked to guess the average human body temperature:
  • Answer: 98.6°F (37°C).
  • (02:01) “The answer is B. 98.6 degrees Fahrenheit or 37 degrees Celsius. Great job if you got that.” — Trusty

2. The History of Body Temperature—Thanks to Dr. Wunderlich!

• Origins: The “98.6°F” figure comes from the 19th-century German doctor, Carl Reinhold August Wunderlich, who appears as a fever-dream character.

  • (05:03) “‘I’m the ghost of Carl Reinhold August Wunderlich, the German physician whose 1868 study established the average human body temperature.’” — Dr. Wunderlich

• How Did He Do It?

  • Took over 1 million temperature readings from 25,000 people over 27 years!
    • (05:37) “‘My study took me 27 years to complete.’” — Dr. Wunderlich

• Thermometer Surprises:

  • The old thermometers were long and took over 15 minutes to register a result.
  • There are four ways to check body temp: mouth, armpit, ear, and rectal (with rectal still considered the most accurate today).
    • (06:29) “...there are four ways to measure this: orally, under the armpit, in your ear, and rectally...” — Trusty
    • (06:45) “‘Rectal thermometers are still considered the most accurate.’” — Dr. Wunderlich

3. Is the 98.6°F Benchmark Still Accurate?

• Modern Trends: The average human body temperature has dropped.

  • Today’s average: 97.9°F (36.6°C)
    • (07:02) “‘But new studies have shown that the temperature of the human body has steadily decreased since the 19th century. The current average is 97.9 degrees Fahrenheit ...’” — Dr. Wunderlich

• Why the Drop?

  • Modern comforts (heating/air conditioning) and better healthcare (fewer infections/inflammations) mean our bodies don’t have to work as hard to stay regulated.
    • (08:19) “Modern researchers hypothesize that heating and air conditioning help maintain stabler external temperatures, while advances in medicine have reduced common infections that cause inflammation and therefore increase body temperature.” — Dr. Wunderlich

4. The Science of Fever & Temperature Regulation

• Why Fever Happens:

  • Fevers indicate the immune system at work—body increases temp to “cook” the virus.
    • (08:35) “‘A fever can indicate the immune system is working properly. ... These chemicals raise your body's temperature, to quote-unquote, cook the virus.’” — Dr. Wunderlich

• Sweating and Shivering:

  • Sweating cools you off when you’re too hot; shivering warms you when cold. It’s all about maintaining “homeostasis”—a physiological balance.
    • (09:05) “‘If your body gets too hot, you sweat ... if your temperature gets too low, we shiver or get chills ... it’s all about balance or homeostasis ...’” — Dr. Wunderlich

5. Animal Temperatures: Cold- vs. Warm-Blooded

• Ectotherms (Cold-blooded):

  • Reptiles, amphibians, most fish, and insects rely on their environment for temp; tend to be long/slender to heat or cool quickly.
    • (13:24) “Ectothermal or cold blooded animals ... tend to be long and slender ... since they depend on the environment for heat and don’t maintain a constant temperature.” — Trusty

• Endotherms (Warm-blooded):

  • Mammals & birds regulate their own heat. Large and/or round shapes help keep heat in.
    • (14:09) “Endothermal or warm blooded animals like mammals and birds tend to be large or round or both ... ” — Trusty

• Bergmann’s Rule:

  • In a species, animals in colder climates tend to be bigger, those in warmer climates smaller.
    • (14:38) “Animals within a given species tend to be larger in colder climates and smaller in warmer climates. This is known as Bergmann’s rule ...” — Trusty

6. Animal vs. Human Temperatures — Who’s Closest?

• Elephants have the closest average body temperature to humans (97.5-99°F/36–37°C).

  • (16:06) “If you said B, elephants. Nice. The average body temperature for elephants is 97.5 to 99 degrees Fahrenheit ... Very close to humans.” — Trusty

• Parrots: Hotter at 103–106°F (39–41°C).

• Dragons: Sorry, they’re not real.

  • (16:06) “Breaking news. Dragons are not real.” — Chet Nickerson

7. Animal Cooling: Sweating, Shivering, Panting

• Most warm-blooded animals shiver for warmth, but few sweat.

• Only some primates and equines (e.g., humans, monkeys, horses, zebras) sweat to cool down.

  • (16:20) “Yes. Many warm blooded animals shiver to increase heat. However, very few sweat to fully cool down. That special salty ability is reserved for primates like humans and monkeys and equines like horses and zebras.” — Trusty

• Others (dogs, frogs, even some birds) pant to cool off.

  • (16:52) “What? No, I'm panting. Panting is how ecto and endothermal animals like dogs, badgers, deer, frogs and even some birds cool down.” — Trusty

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Notable Quotes & Memorable Moments

• (01:19) “‘This is Chet Nickerson with some breaking who smarted News. Everyone’s favorite trusty narrator is running a low GR fever of 100 degrees Fahrenheit ... This is an ongoing story. I’ll be back soon with further developments.’” — Chet Nickerson (humorous “news flash” style)
• (05:54) “‘Once I had to use a foot long thermometer that took more than 15 minutes to register a reading.’” — Dr. Wunderlich
• (06:11) “‘Mouth? Who said anything about mouth.’” — Dr. Wunderlich (teasing Trusty about thermometer placement)
• (08:35) “‘A fever can indicate the immune system is working properly. When the body detects an intruding virus, the immune system releases inflammatory chemicals. These chemicals raise your body's temperature, and “cook the virus”.’” — Dr. Wunderlich
• (14:38) “Animals within a given species tend to be larger in colder climates and smaller in warmer climates. This is known as Bergmann’s rule ...” — Trusty
• (16:06) “‘Breaking news. Dragons are not real.’” — Chet Nickerson

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Timestamps for Important Segments

• [02:01] – What is the average human body temperature?
• [05:03] – Dr. Wunderlich “appears” and explains his temperature study
• [06:45] – How temperature is measured, rectal vs. other methods
• [07:02] – The average body temperature is lower today than in 1868
• [08:35] – Why fevers happen (immune response)
• [10:24] – Difference in body temps/scenarios for lizards (cold-blooded) vs. humans
• [13:24] – Cold- vs. warm-blooded animals and their bodys’ shapes/sizes
• [14:38] – Bergmann’s rule explained
• [16:06] – Elephant body temperature compared to humans
• [16:20] – How animals regulate temperature (sweating, shivering, panting)

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Tone and Humor

Throughout, the episode’s lighthearted and conversational style shines. Trusty navigates illness with help from the over-the-top Chet Nickerson and a humorous cameo from Dr. Wunderlich. Frequent “news bulletins,” puns (like “whiff of science and history”), quizzes for listeners, and playful banter keep young minds engaged and entertained.

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Conclusion

Who Smarted? delivers an accessible, funny, and informative journey through the science and history of body temperature. The big takeaways:

• “Normal” body temperature isn’t set in stone—it can change over time and between individuals.
• The “98.6°F” standard has a cool backstory involving years of patient (and patient) research.
• Modern lifestyle and medicine have shaped our baseline body temps.
• Humans and animals regulate temperature in fascinatingly diverse ways.

Bonus: Now you’ll remember not to panic if your thermometer doesn’t read exactly 98.6°F... and that dragons, sadly, aren’t real—but science adventures can be just as cool.

Transcript

[Jane Lindholm]

Kids, you have a lot of questions.

[Trusty (Narrator)]

Is a crocodile a dinosaur?

[Chet Nickerson]

Why do people vote?

[Jane Lindholm]

How does your food turn into your poop?

[Trusty (Narrator)]

But why?

[Jane Lindholm]

A podcast for curious kids has answers. I'm Jane Lindholm. Join me as we dig deep into everything from science to history, nature, emotions, and sometimes even the weird.

[Chet Nickerson]

Why are jellyfishes made of jelly?

[Carl Reinhold August Wunderlich]

Or are they made out of jelly?

[Trusty (Narrator)]

Find.

[Jane Lindholm]

But why? Wherever you get your podcasts.

[Trusty (Narrator)]

And now it's time for who's Smarted? Psst. Hey, smarty pants. Sorry if I sound funny. I'm a little stuffed up. I've got a bad cold.

[Chet Nickerson]

Bless you, Trusty.

[Trusty (Narrator)]

Thank you. Fortunately, news reporter and my best pal, Chet Nickerson has been kind enough to offer to take care of me.

[Chet Nickerson]

That's right. Not to mention there aren't very many trusty narrators left in the wild. So when one gets sick, it's breaking news. And speaking of breaking, let's see if your fever has broken yet. Say ah.

[Trusty (Narrator)]

Ah.

[Chet Nickerson]

Let's see. Oh boy.

[Trusty (Narrator)]

What does it say?

[Chet Nickerson]

This is Chet Nickerson with some breaking who smarted News. Everyone's favorite trusty narrator is running a low GR fever of 100 degrees Fahrenheit, or 37.8 degrees Celsius. This is an ongoing story. I'll be back soon with further developments.

[Trusty (Narrator)]

I gotta say, Chet, I really don't think my low fever is news.

[Chet Nickerson]

Trust me, trustee, I know news. And the fact that your body temperature is 1.4 degrees Fahrenheit or 0.8 degrees Celsius higher than the average human body temperature is definitely news. Or at least it's new cuz it wasn't like that yesterday.

[Trusty (Narrator)]

Right, smarty pants? Have you ever had a fever? You probably have. Maybe it was a little higher than the average human body temperature. Or maybe it was a lot. But before we get into that, just what is the average human body temperature? Is it a 96.8 degree F, B, 98.6 degrees Fahrenheit, or C 99.9 degrees Fahrenheit? The answer is B. 98.6 degrees Fahrenheit or 37 degrees Celsius. Great job if you got that. But why is.

[Chet Nickerson]

Here you go, trusty. Some delicious mouth watering meat cake broth soup. This will have you feeling right as rain. Oh, and speaking of rain, we're due for some heavy rains moving in from the south.

[Trusty (Narrator)]

Thanks, Chet, but maybe next time give me a little warning before you stick a spoon in my mouth.

[Chet Nickerson]

Speaking of warnings, Chet Dickerson reporting. A coastal flood warning has just Been issued due to heavy rains and winds.

[Trusty (Narrator)]

Oh, wow. Guess I picked the right day to be sick in bed. But while I rest and try to lower my body temperature. Smarty pants, now's a good time to learn more about body temperature. Like, why is 98.6 degrees Fahrenheit the average human body temperature? How does your body regulate temperature? And what happens when your body gets too hot or too cold?

[Chet Nickerson]

Speaking of cold, there's a cold front moving in for the.

[Trusty (Narrator)]

Whoa, whoa, whoa, Chet. First, it's time for another whiff of science and history on who smarted.

[Chet Nickerson]

Who smarted, who smarted smart? Is it you? Is it me? Is it science or history? Listen up, everyone. We make smarting lots of fun on who's smart and.

[Trusty (Narrator)]

Okay, smarty pants. 98.6 degrees Fahrenheit, or 37 degrees Celsius is the average human body temperature. But who actually averaged it out? And how did they do it?

[Chet Nickerson]

Great questions, trusty. I'd love to help answer them, but I need to check on the cookies I'm baking.

[Trusty (Narrator)]

Cookies are good for a fever.

[Chet Nickerson]

No, but I figured if I'm going to be stuck in the house all day with a sick narrator during heavy rains, a coastal flood and a cold front, I may as well bake cookies in your kitchen with your cookie dough. Be right back.

[Trusty (Narrator)]

Anyway, like I was saying, smarty pants, somebody had to figure out what the average human body temperature was. The question is, who?

[Carl Reinhold August Wunderlich]

I think it was me.

[Chet Nickerson]

Whoa.

[Trusty (Narrator)]

Where'd you come from? I didn't hear you come in.

[Carl Reinhold August Wunderlich]

That is because I did not come in. I am a figment of your fever dream. Air narrator.

[Trusty (Narrator)]

Fever dream? I really am sick.

[Carl Reinhold August Wunderlich]

And I'm the ghost of Carl Reinhold August Wunderlich, the German physician whose 1868 study established the average human body temperature.

[Trusty (Narrator)]

Hey, smartypants, how do you think Dr. Wunderlich calculated the average human body temperature? Did he A, take his own temperature once and say that's that, or b, take over 1 million temperatures from 25,000 different people? If you said A, take his own temperature once and say that's that, that's incorrect.

[Carl Reinhold August Wunderlich]

I wish.

[Trusty (Narrator)]

Which means Dr. Carl took over 1 million temperatures from 25,000 different people. That's a lot of temperature taking.

[Carl Reinhold August Wunderlich]

Oh, yeah. My study took me 27 years to complete.

[Chet Nickerson]

Whoa.

[Carl Reinhold August Wunderlich]

Yeah. Vo is right. Once I had to use a foot long thermometer that took more than 15 minutes to register a reading.

[Trusty (Narrator)]

Fifteen minutes? That's a long time to hold a thermometer in your mouth.

[Carl Reinhold August Wunderlich]

Mouth? Who said anything about mouth.

[Trusty (Narrator)]

Oh, no.

[Carl Reinhold August Wunderlich]

Oh, yeah.

[Trusty (Narrator)]

Are you saying what I think you're saying?

[Carl Reinhold August Wunderlich]

What, that I used a rectal thermometer that went in people's butts? Well, that is not what I'm saying. I used an armpit thermometer like we have today.

[Trusty (Narrator)]

Phew. As you know, body temperature is a way of measuring how your body gives off heat. And there are four ways to measure this. Orally, AKA by mouth, under your armpit, in your ear, and rectally, AKA in your butt.

[Carl Reinhold August Wunderlich]

However, rectal thermometers are still considered the most accurate. Speaking of which, did you know that the average human body temperature is lower now than it was in 1868?

[Trusty (Narrator)]

Lower. Really? Does that mean your readings were inaccurate?

[Carl Reinhold August Wunderlich]

On the contrary. Many doctors today still use 98.6 degrees Fahrenheit as a benchmark. But new studies have shown that the temperature of the human body has steadily decreased since the 19th century. The current average is 97.9 degrees Fahrenheit, 36.6 degrees Celsius.

[Trusty (Narrator)]

That's quite a drop.

[Carl Reinhold August Wunderlich]

Gesundhteit. That means health in German.

[Trusty (Narrator)]

Thanks. Hey, smarty pants, why do you think the average human body temperature has decreased over time? Is it because, A, thanks to video games and YouTube, things are a lot cooler today than in 1868? B the weather was hotter in the past, or C, modern developments have influenced the body's temperature regulation? If you said A, things are cooler today because of video games, you're thinking of a different kind of cool. If you said, B, the weather was hotter in the past, global warming is causing a steady increase in average temperatures. So it's actually hotter on average today than it was back then. But if you said C, modern developments have influenced the body's temperature regulation, you're correct.

[Carl Reinhold August Wunderlich]

Modern researchers hypothesize that heating and air conditioning help maintain stabler external temperatures, while advances in medicine have reduced common infections that cause inflammation and therefore increase body temperature.

[Trusty (Narrator)]

Like a fever caused by a cold?

[Carl Reinhold August Wunderlich]

Precisely. In fact, a fever can indicate the immune system is working properly. When the body detects an intruding virus, the immune system releases inflammatory chemicals. These chemicals raise your body's temperature, und quote, unquote, cook the virus. Sounds very uncomfortable.

[Trusty (Narrator)]

Haha, it sure is. One minute I'm sweating, the next I'm shivering.

[Carl Reinhold August Wunderlich]

That is natural air. Narrator. If your body gets too hot, you sweat to cool off. If your temperature gets too low, we shiver or get chills. To increase is all about balance or homeostasis, the tendency toward equilibrium in a physiological process. In this Case the body's temperature regulation.

[Trusty (Narrator)]

Danke, Doctor. I feel better already.

[Carl Reinhold August Wunderlich]

That is all for me. So long, air narrator. Get well soon, Aufier then.

[Chet Nickerson]

All right, who wants meat cake? Hey, that's my line.

[Trusty (Narrator)]

Sorry, Mom. He's just trying to help me.

[Chet Nickerson]

Your mom? Your mom isn't here.

[Trusty (Narrator)]

Oh, boy. This fever has me seeing and hearing things.

[Chet Nickerson]

That's okay. Here, have a cookie.

[Trusty (Narrator)]

Oh, speaking of food, would you mind feeding my pet lizard, Thin Lizzy? He was a gift from my pal, dino hunter Robert Maroon. He's over there in his tank.

[Chet Nickerson]

Sure thing, Trusty. Should I turn on his heat lamp too?

[Trusty (Narrator)]

No, he's fine for now. Right now he's around 70 degrees Fahrenheit or 21.1 degrees Celsius.

[Chet Nickerson]

What? Isn't that really low for humans?

[Trusty (Narrator)]

Yeah. If a human's body temperature drops below 1095 degrees Fahrenheit, that's hypothermia. Very dangerous. But for a cold blooded lizard like Thin Lizzy, that's not a problem. Hey, smarty pants. Now that you know how humans regulate body temperature, what about animals? Do they have different average body temperatures? And how do they regulate themselves?

[Chet Nickerson]

This is Chet Nickerson with breaking news.

[Trusty (Narrator)]

No, no, no breaking news. Just a short break. This show is sponsored by ixl. You know that as the trusty narrator, I'm always eager to learn new things. Even if I prefer to do it from the comfort of my own home. That's why I'm excited to share a fantastic resource for homeschool families looking to start the new year with confidence, ixl. IXL is an award winning online learning platform that adapts to each child's level, making it the perfect companion for homeschooling. With interactive practice across math, language, language arts, science and social studies. From Pre K through 12th grade, IXL offers a personalized and flexible learning experience. What I love most about IXL is how it keeps kids motivated with challenges, awards and moments of celebration. Plus the real time feedback and progress tracking give parents peace of mind knowing their children are learning effectively. My niece used it to stay on top of subjects that she found challenging. And and it was incredibly helpful to her. So if you're looking to make an impact on your child's learning this year, get IXL now. And as a special offer for our listeners, you can get an exclusive 20% off an IXL membership when you sign up today at ixl.com smarted. That's 20% off an IXL membership at ixl.com smartEd.

[Snoop]

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[Trusty (Narrator)]

Now back to who Smarted? Okay, smarty pants. Earlier you learned how humans regulate their body temperature, but what about animals?

[Chet Nickerson]

What about them?

[Trusty (Narrator)]

Well, when it comes to animals and body temperature regulation, there's only one factor to consider. Any guesses what it is? Is it A, if the animal is warm or cold blooded, B if the animal is large or small, or C what climate the animal lives in?

[Chet Nickerson]

Hmm, they all seem like right answers.

[Trusty (Narrator)]

You got it, Chet. All three are right. An animal's warm or cold bloodedness, its size and shape and its environment all influence how it regulates body temperature. Not only that, the factors play off of each other. Ectothermal or cold blooded animals like reptiles, amphibians, insects and most fish tend to be long and slender like Thin Lizzy. Their shape allows them to quickly heat up or cool down since they depend on the environment for heat and don't maintain a constant temperature.

[Chet Nickerson]

I see, which is why you have a heat lamp. When they want heat, they can bask under it, and when they're too warm, they can go to the other side of the tank to cool off.

[Trusty (Narrator)]

Exactly. In contrast, endothermal or warm blooded animals like mammals and birds tend to be large or round or both. If a large endothermal animal like an elephant were cold blooded, it'd take too long for it to heat up or cool down, putting it in danger. If a small endothermal animal like a mouse wasn't round, it would struggle to retain the heat it generates.

[Chet Nickerson]

Very interesting. So what about the final factor? An animal's climate?

[Trusty (Narrator)]

Animals within a given species tend to be larger in colder climates and smaller in warmer climates. This is known as Bergmann's rule, named after German biologist Carl Bergmann. Oh boy. Another German, huh? Nothing. Anywho, Bergmann's rule has to do with body temperature. Because smaller animals have a higher surface to volume ratio than than larger animals. This causes them to lose heat more quickly and therefore survive better in warmer climates.

[Chet Nickerson]

Which means the opposite must be true of larger animals. Their lower surface to volume ratio causes them to lose heat more slowly, which helps them survive in colder climates.

[Trusty (Narrator)]

Exactly. Hey smarty pants. Which of these animals do you think has the closest average temperature to humans? Is it A, parrots, B, elephants or C dragons? Although dragons are super cool and I wish they were real. They're not. If you said A, parrots. Sorry, also wrong. The average body temperature range for parrots is 103 to 106 degrees Fahrenheit, or 39 to 41 degrees Celsius. But if you said B, elephants. Nice. The average body temperature for elephants is 97.5 to 99 degrees Fahrenheit, or 36 to 37 degrees Celsius. Very close to humans.

[Chet Nickerson]

Breaking news. Dragons are not real.

[Trusty (Narrator)]

Yeah, I think everyone knew that. But what you might not know is do animals use methods like humans such as sweating to cool down or shivering to heat up?

[Chet Nickerson]

Ah, you're right. I don't know.

[Trusty (Narrator)]

The answer is yes. Many warm blooded animals shiver to increase heat. However, very few sweat to fully cool down. That special salty ability is reserved for primates like humans and monkeys and equines like horses and zebras.

[Chet Nickerson]

So if most animals don't sweat to cool down, what do they do? Oh no. Trustee, are you okay? Is the fever making you crazy?

[Trusty (Narrator)]

What? No, I'm panting. Panting is how ecto and endothermal animals like dogs, badgers, deer, frogs and even some birds cool down.

[Chet Nickerson]

Ah, yes, of course. By the way, did you know there's a German doctor eating cookies in your kitchen? He just tried to take my temperature.

[Trusty (Narrator)]

Oh boy. A Texas sized shout out to smarty fan banner in Austin, Texas. I hear before you even say hello in the morning you say I want to listen to who's smarted. I love that. I also love that you giggle in the back of the car while learning new things. Keep on smarting on my friend. This episode Body Temperature was written by Dan Hatestecold and voiced by Adam Fever Dream Davis, Simmering Salmon Trader and Jerry Colber. Technical direction and sound design by Josh Hot Flashing Han who Smarted is recorded and mixed at the Relic Room studios. Our associate producer is Max Mercury Kamasky. The theme song is by Brian Sweaty Sheets Suarez with lyrics written and performed by Adam Tex. Davis who Smarted was created and produced by Adam Tex Davis and Jerry Colbert. This has been an Atomic Entertainment production.