Hey there, Kaylee here with DNews.

嘿！你們好！我是 DNews 的 Kaylee。

Throughout the day, your body temperature can vary depending on the time, your level of activity, and age, although it averages to about 98.6 degrees Fahrenheit, or 37 degrees Celsius.

一整天下來，體溫會隨著時間、活動量、或是年齡而有所變化，雖然平均體溫會是在華氏 98.6 度、或是攝氏 37 度。

Fun fact: at night, your core body temperature drops slightly, allowing you to fall asleep.

有趣的是：在晚上，核心體溫會稍微地降低，讓你能安穩的睡著。

But a temperature over 100.4 degrees Fahrenheit, or 38 degrees Celsius, usually means that you have a fever caused by infections or an illness.

但是當溫度高於華氏 100.4 度或是攝氏 38 度，通常表示受到病菌或是疾病的感染因而發燒。

Fever, also known as pyrexia, and it's an important part of the immune system’s response to an invading bacterium or virus.

發燒，也稱之為發熱，是一種重要的免疫系統反應，會對細菌或病毒的入侵有所反應。

The immune system produces pyrogens, which travel through the blood to the brain, finally reaching the hypothalamus, the body’s thermostat.

免疫系統會產生熱源，透過血液傳送到頭腦，最後則到達中樞神經下視丘，也就是身體的體溫定位點，

This then raises the body’s temperature above the normal range, and, lo and behold, you are lying in bed, covered in blankets, fondly remembering the times when you felt normal.

它會使體溫高於正常值，然後你看，你就會躺在床上，蓋著毛毯，想著當初活潑亂跳的時候。

If you’re really uncomfortable, you might decide to take an antipyretic, or fever-reducing medication.

如果真的不舒服，就應該要吃退燒藥、或是能減輕發燒的藥。

This will inhibit the enzyme cyclooxygenase and reduce the level of prostaglandin E2 in the hypothalamus.

這樣的藥會抑制環氧酵素，降低中樞神經下視丘分泌的前列腺素 E2。

In plain English, the medicine overrides the signals that tell your hypothalamus to elevate your body temperature and will reduce it instead.

簡單來說，這樣的藥會撤銷中樞神經下視丘要升溫的訊號，進而降低溫度。

But having a fever is actually a good sign! It means that our bodies are beginning to fight off the infection.

但發燒實際上是件好事！意思是，我們的身體會開始抵抗這樣的感染。

Previously, scientists believed that the elevated temperature might inhibit the growth of some viruses or bacteria and potentially even kill them.

在這之前，科學家們認為，體溫的升高可能會抑制某些病毒或是細菌的孳生，或甚至是消滅他們。

However, a study published in the Journal of Leukocyte Biology found that a fever also helps certain types of immune cells to do their job better.

然而，一個在 Leukocyte Biology 期刊所發表的研究指出，發燒也可以使得某些部分的免疫細胞表現得更為突出。

In the study, researchers injected mice with an antigen and then monitored the activation of a type of lymphocyte called CD8+ cytotoxic T cells, which are capable of killing cells infected with viruses and even cancer cells.

在這研究中，研究人員將抗原注射到老鼠身上，然後觀察其之後淋巴球的活化，也就是所謂的细胞毒性T細胞，能消滅受到病毒感染的細胞，甚至是殺死癌細胞。

Half of the mice’s body temperatures were raised 2 degrees Celsius while the other half was left alone.

一半的老鼠體溫都提高了攝氏 2 度，但另一半的體溫不變。

The results showed that the mice whose temperature was raised had more of the CD8+ T cells than the control mice.

這樣的研究結果顯示出，這些溫度升高的老鼠比起那些注射過的老鼠擁有較多的细胞毒性T細胞。

This suggests that elevated body temperature may enhance the function of the immune system, meaning that we can get better faster.

這表示，體溫升高可能可以增強免疫系統，意思是我們可以康復得很快。

If left untreated, a fever will normally only last two or three days, but the duration can vary.

如果我們不理會發燒，正常來講就只是會持續個兩天或三天而已，但要看情況。

So, as uncomfortable as it is, you may be better off not taking any medicine to reduce it; however, it is important to note that this is only recommended for mild fevers.

所以，雖然發燒很不舒服，但最好不要吃任何的藥來退燒 。但是，也要記住，這樣的情況只適用於輕微發燒的人。

If your body temperature is over 108 degrees Fahrenheit, you may be in trouble; if it becomes too high, you’ll definitely wanna go see a doctor.

如果體溫超過華氏 108 度可能就會有危險；如果體溫太高就得去醫生。

Fevers from infections rarely get this high, and are instead usually caused by heat strokes.

感染造成的發燒很少會有這樣高的體溫， 通常這樣的高溫是因為中暑。

See, when your body temperature gets high, you sweat to cool down. As a consequence, your body loses water and salt, which are essential for normal functioning.

當體溫升高時，就會流汗來降低體溫。因此，身體會流失水分及鹽分，而這些是身體必要的機能養分。

And if you’ve already lost a lot of water and become dehydrated, you may not be able to sweat fast enough to dissipate the heat, causing your body temperature to rise even further.

而如果已經流失太多的水造成脫水，可能就無法再排出足夠的汗水來發散體熱，因而造成體溫更為上升。

You know how your parents always tell you to stay hydrated when you are sick? Yeah, that’s why.

現在知道為什麼父母親總是會叮嚀你生病時要多喝水了吧？對！這就是為什麼！

At such a high temperature, proteins and cell membranes, especially in the brain, can be destroyed or malfunction.

這麼高的溫度下，特別是位於腦袋中的蛋白質和細胞膜會因此被破壞或是無法正常運作。

Heart muscle cells and blood vessels can break down, damage can occur to internal organs, and, in the worst case, a fever can cause death.

心臟肌細胞和血管也會因而斷裂，內臟也會因而受到傷害，更糟的情況甚至會造成死亡。

While a fever may help you get over your infection faster, the brain and body can only handle so much.

雖然發燒可以讓你快速康復，但腦袋和身體也只有一定的承受度。

So, what’s the worst fever that you’ve ever had? And what do you normally do to get over it?

你曾經有過很不舒服的發燒經驗嗎？那通常都怎麼康復的呢？

Let us know in the comments and if you want to know more about temperature’s effect on sleep, head over to my personal channel, Explorium, to find out if sleeping naked is better for you.

在留言區跟我們分享吧！如果還想要了解有關溫度會影響睡眠的相關議題，可以來我的個人頻道 Explorium，你會發現，裸睡可以使你們的睡眠品質更好。

See, when you go to bed at night, your core body temperature decreases by about half a degree Celsius.

當晚上要睡覺時，體溫會降低大約是攝氏 0.5 度。

Now, that might not seem like a big change, but it's thought that some insomniacs may have a hard time getting to bed because they have impaired thermoregulatory systems, making it harder to lose that extra heat.

聽起來是沒有多大的差距，但有些失眠者可能會因此很難入睡，因為他們的體溫調節中樞功能有所受損，使得他們無法排出多餘的體熱。

If you’re on mobile, it will be the first link in the description.

如果是用手機看的話，下面的資訊欄裡的第一個連結就可以到我的頻道。

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謝謝收看 DNews。訂閱的話可以收看更多影片哦！