It's a handy number to know if you're trying to game the thermometer to get out of school.

如果你想玩體溫計出校門，這是個很方便的數字。

But new studies have uncovered that the rial average human body temperature is actually lower than that, and it's dropping.

但新的研究發現，里亞爾人的平均體溫其實比這個低，而且還在下降。

So where does this classic number of 37 degrees Celsius even come from anyway?

那麼，37攝氏度這個經典數字到底是怎麼來的呢？

Well, in 18 51 a German doctor named Carl Wunderlich conducted a years long study.

好吧，在1851年，一個叫卡爾-吳德利希的德國醫生進行了多年的研究。

He went room to room in his hospital with a thermometer, taking the temperatures of some 25 different patients to try and pin down the average human body temperature.

他帶著體溫計在醫院裡挨個房間測量大約25個不同病人的體溫，試圖確定人體的平均溫度。

And he did 17 years later when he published a paper with that well known metric of 37 degrees.

而他在17年後發表了一篇論文，用那個眾所周知的度量標準37度。

He also gave us the first quantitative measurement for determining if someone has a fever 38 degrees and above.

他還為我們提供了第一個量化的測量方法，用於判斷某人是否發燒38度及以上。

That's a favor, baby, and then for the next 140 years, we just accepted this number as correct.

這是一個忙，寶貝，然後在接下來的140年裡，我們只是接受這個數字是正確的。

Despite the fact that Doctor of Wonderlic collected this data using a comically large foot long wooden thermometer that had to be held in a patient's armpit for 20 minutes.

儘管神奇博士使用一個滑稽的大尺長的木製體溫計收集了這些數據，但這個體溫計必須在病人的腋窩裡放置20分鐘。

Because, believe it or not, portable thermometers small enough to fit under your tongue weren't invented until 18 66.

因為，不管你信不信，小到可以放進舌頭下面的便攜式溫度計，直到1866年才被髮明出來。

So it wasn't until the 19 nineties that another doctor decided to revisit this question using more modern equipment.

所以直到1990年代，又有一位醫生決定用更現代化的設備重新審視這個問題。

And he found that, yeah, the average human body temperature is actually around 36.8 degrees Celsius on it varies throughout the day throughout someone's hormonal cycle throughout someone's lifetime.

他發現，是的，人的平均體溫其實是36.8攝氏度左右，它在一天之內都會有不同的變化，在人的一生中，整個人的荷爾蒙週期都會有不同的變化。

So determining whether or not someone actually has a fever depends on a lot of different factors, which is pretty important to account for in a clinical setting.

所以，判斷一個人是否真的發燒取決於很多不同的因素，這在臨床上是相當重要的考慮。

And then ah, 2020 study out of Stanford University took hundreds of thousands of measurements and found that the average body temperature was around 36.4 degrees Celsius.

然後啊，2020年斯坦福大學的研究進行了數十萬次測量，發現平均體溫在36.4攝氏度左右。

This made them ask, what if this drop in average temperature isn't entirely due to the difference in thermometer accuracy, but is instead because average human body temperature is actually falling?

這讓他們不禁要問，如果這種平均溫度的下降並不完全是由於溫度計精度的不同，而是因為人類平均體溫實際上在下降呢？

To answer this question, they embarked on a fascinating research journey that took a historical view of human temperature data in the U.

為了回答這個問題，他們開始了一段引人入勝的研究之旅，對美國的人類溫度數據進行了歷史考察。

S.

S.

They used huge existing data sets ones measuring from 18 60 to 1940 1971 to 1975 2007 to 2017.

他們使用了龐大的現有數據集那些從18 60到1940年1971年到1975年2007年到2017年測量。

To get a sense of how human body temperature may have changed over the past 150 odd years.

為了瞭解過去150多年間人類體溫可能發生的變化。

And each of these groups, after adjusting for age, height, wait and other variables show a clear decrease in average temperature over time.

而這些群體，在調整了年齡、身高、等待等變量後，每一個群體的平均溫度都會隨著時間的推移而明顯下降。

There's also a drop between groups as we move from past to present.

當我們從過去到現在的時候，群體之間也會有一個落差。

Even with groups were comparable thermometers were used, so it's clearly not just in equipment issue.

即使與各組都使用了可比的溫度計，所以這顯然不只是在設備問題。

So what he's going on?

那他是怎麼回事？

The researchers hypothesize that this decrease in average body temperature over time could be due to a decrease in resting metabolic rate.

研究人員推測，這種平均體溫隨時間的下降可能是由於靜息代謝率的下降。

Essentially, that's how hard your body is working when at rest.

本質上，這就是你的身體在休息時的工作強度。

They also take it one step further, saying this reduction in resting metabolic rate could be do toe lowered overall inflammation.

他們還更進一步說，這種靜息代謝率的降低可能是做趾降低整體發炎。

See, modern populations typically have lower chronic infection, better dental hygiene and just generally improved living in hygiene standards.

你看，現代人一般慢性感染率較低，牙齒衛生較好，只是生活衛生水準普遍提高。

This could be why people in wealthier countries like the U.

這可能是為什麼像美國這樣的富裕國家的人。

S.

S.

Are experiencing this drop in body temperature over time.

正在經歷這種體溫的下降，隨著時間的推移。

But there's other data that throws that hypothesis off because another recent study tracked the average body temperature of over 5000 members of the demonic, a community in the remote Bolivian rainforest.

但還有其他數據讓這個假設落空了，因為最近的另一項研究追蹤了超過5000名惡魔成員的平均體溫，這是玻利維亞偏遠雨林中的一個社區。

That doesn't have as much access to that modern health care that the Stanford study proposed as the potential cause of the temperature drop.

那沒有斯坦福大學的研究提出的那種現代醫療服務，作為氣溫下降的潛在原因。

And even still, the average Toumani body temperature in 2002 was around 37 degrees Celsius, while the 2020 average was 36.5.

而即便如此，2002年圖馬尼的平均體溫還是在37攝氏度左右，而2020年的平均體溫是36.5。

So now we have a clearly documented decrease in body temperature in populations that are in very different parts of the world, and we still don't know exactly why it could still be due to that improvement in healthcare and sanitation that we mentioned already.

所以現在我們有明確的記錄，在世界不同地區的人群中，體溫下降了，我們仍然不知道到底為什麼可能還是因為我們已經提到的醫療和衛生條件的改善。

It could be due to greater temperature control of our surroundings through things like electric fans and air conditioning.

可能是由於通過電風扇和空調等東西對我們周圍環境的溫度控制較好。

It could be because people are less active than we were 200 years ago and get this.

可能是因為人們的活躍度不如我們200年前，所以才會有這樣的情況。

Some scientists have even suggested that using MAWR antibiotics has reduced our bodies microbial diversity so much that it's had an impact on our overall temperature like because we no longer have the heat from all those microbes were now colder people, which is totally wild, so there's still lots to explore here on board.

一些科學家甚至提出，使用MAWR抗生素已經降低了我們身體的微生物多樣性，以至於對我們的整體溫度產生了影響，比如因為我們不再有所有這些微生物的熱量是現在更冷的人，這是完全野生的，所以在船上還有很多東西可以探索。

Whatever the reason, the fact remains, no matter how dorky you may feel like you are, humans are getting cooler over time.

不管原因是什麼，事實是，不管你覺得自己有多呆板，人類都會隨著時間的推移變得越來越酷。

On speaking of human body temperature, one place you really want to keep cool is the Australian Outback.

說到人的體溫，真正想保持涼爽的一個地方是澳洲內陸地區。

Be sure to check out lightspeed, our new docuseries on an incredible solar car race across the continent.

請一定要看看我們的新系列片 "光速"，它講述了一場不可思議的橫跨大陸的太陽能汽車競賽。

New episodes will be released every Monday through January 4th.

新劇集將在每週一到1月4日發佈。

And make sure you subscribe to seeker so you don't miss one.

而且一定要訂閱seeker，這樣才不會錯過一個。

Thanks for watching, and I'll see you next time.

謝謝你的觀看，我們下次再見。