How does extreme heat affect your body? - Carolyn Beans

譯者: Lilian Chiu 審譯者: Zoe Walmsley

The year is 2050 and your morning is not off to a good start.

時間來到 2050 年，

一早起來就一堆問題。

School is closed for yet another heat day,

學校因為氣溫過高再次停課，

meaning the kids need to stay home and the AC needs to stay on.

也就是說，孩子得待在家裡，

冷氣也得一直開著。

Your usual babysitter can’t come help

你平時用的保姆無法來幫忙，

because the rails for their commuter train were warped by the heat.

因為通勤火車的鐵軌 在高溫下扭曲變形了。

And to make matters worse, your dog is desperate for a walk,

更糟的是，你的狗還非常想去散步，

but the pavement is hot enough to give third degree burns

但人行道熱到能造成三度灼傷，

to any paw or person that touches it.

動物的爪或人的腳都無一倖免。

In many parts of the world, this sweltering future is already here.

在世界上的許多地方，

這個酷熱的未來已經開始了。

On average, heat waves are happening more often with greater intensity

平均而言，熱浪的頻率變得越來越高，

強度越來越強，

and for longer durations.

持續的時間也越來越長。

But according to a 2022 projection,

但根據一個 2022 年的預測，

by 2050, Earth’s mid-latitudes could be experiencing extreme heat

到 2050 年時，

地球上的中緯度地區 可能會出現極端高溫，

between 90 and 180 days a year,

一年有 90 到 180 天 都是這樣的狀態，

with tropical regions enduring even more.

熱帶地區甚至更嚴重。

So, how hot is too hot, and what can people do to handle the heat?

所以，要多熱才算過熱？ 人又該如何因應高溫？

While human bodies are decent at managing temperature,

儘管人體調節體溫的功能還不錯，

our cooling mechanisms only work under the right conditions.

我們的冷卻機制 還需對的條件才能運作。

When air temperatures climb,

當空氣溫度上升，

the hypothalamus tells blood vessels near the skin to widen,

下視丘會讓皮膚附近的血管擴張，

allowing more blood to flow near the body's surface and release heat.

讓更多血液流向體表，

達到散熱的目的。

This hormonal cascade also turns on our sweat glands.

這種荷爾蒙的連鎖反應 也會啟動我們的汗腺。

As sweat evaporates, it pulls the heat from our skin.

汗水蒸發的同時，皮膚也在散熱。

But if humidity is high, the rate of evaporation slows and eventually stops.

但濕度高時，

蒸發速度減慢，甚至會停下。

Scientists use this principle to track humidity with a metric

科學家基於這個原理，

使用一個名為濕球溫度的 測量方式來測量濕度：

called wet-bulb temperature,

in which they wrap a wet, room temperature cloth around a thermometer

用一塊室溫的溼布把溫度計包起來，

to see if evaporation will lower the reading.

檢視蒸發會不會讓溫度降低。

If it doesn't, it's too humid for sweat to cool us off.

沒有降低的話就表示濕氣太高，

流汗也不能讓身體降溫。

A wet-bulb temperature of roughly 35°C

攝氏 35 度 C 左右的濕球溫度

is generally considered the limit of human survival,

普遍被認為是人類生存的上限，

though current temperatures rarely reach this threshold.

不過目前的氣溫很少達到這個門檻。

The US National Weather Service uses the relationship between humidity

美國國家氣象局使用的熱指數

and air temperature as the basis for their heat index.

是以濕度和氣溫兩者的關係當作基礎。

As those two metrics rise, so too does the heat index;

隨著這兩個指數上升，

熱指數也會增加；

and heat is considered dangerous

而當熱指數高過 39.4 度 C，

if the index climbs above 39.4°C.

就被認為是危險的酷熱了。

That’s 103°F.

換算成華氏是 103 度。

But even a lower heat index can be hazardous over multiple days.

但較低的熱指數若持續數日， 也會造成危險。

A heat wave is a streak of two or more days of unusually hot weather

熱浪是指在某一個地方的某一季

出現連續兩天以上的異常炎熱天氣。

for a place and season.

For example, a string of 32°C days in Houston, Texas,

比如，在德州的休士頓， 連續數日攝氏 32C 的氣溫，

is standard in the summer,

在夏天算是標準，

but would constitute a heat wave in March.

但如果在三月，就算是熱浪。

And the impact of these events touches nearly every aspect of daily life.

而這會影響日常生活的每個面向。

Imagine a June heat wave strikes a tropical city.

想像一下，在六月， 熱浪襲擊了一個熱帶城市。

The first to experience effects are outdoor workers.

最先受到影響的是戶外工作者。

Their excessive sweating leads to dehydration and muscle pain

過量出汗導致脫水和肌肉疼痛，

known as heat cramps.

就是一般所知的熱痙攣。

If they push on, their conditions could worsen

如果置之不管，狀況會再惡化，

to heat exhaustion and even heat stroke—

導致熱衰竭，甚至熱中暑──

a life-threatening ailment that occurs when a body’s temperature exceeds 40°C.

當體溫超過 40 度C 對生命構成威脅的一種熱傷害。

Medical emergency calls spike across the city,

城市各地的緊急醫療電話被打爆，

often for children and people who are pregnant or elderly.

救援對象通常是兒童、 孕婦，或老年人。

The heat also increases hospital visits for heart, kidney,

高溫也讓更多人因為心臟、

腎臟，以及肺部的 症狀前往醫院求診，

and lung-related conditions,

creating an influx of patients that threatens to overwhelm medical providers.

病患的大量湧入， 讓醫療機構難以承受。

Over the following week, the city slows to a crawl.

接下來的一週，城市的運作近乎停滯。

Schools and construction sites close.

學校和建築工地都關閉了。

Airplanes need to reduce their weight limits to take off,

飛機需要降低重量限制才能起飛，

bumping countless travelers from their flights.

無數旅客無法搭上他們的航班。

Restaurants shut down as overheated kitchens become unbearable.

餐廳停止營業，

因為廚房熱到沒人能夠忍受。

Residents who remain inside with air conditioners stay safe.

待在室內使用冷氣還能保持安全。

But blasting AC isn’t cheap,

但狂開冷氣一點也不便宜，

and many families have to choose between keeping cool and staying fed.

吹冷氣還是吃飯對許多家庭變成抉擇。

Either way, if the heat continues,

無論如何，如果高溫持續下去，

the stress of these air conditioners could overwhelm the power grid,

開冷氣造成的負擔也遲早會拖垮電網。

potentially leading to city-wide outages.

甚至可能導致全市大停電。

These consequences are all very real.

這些後果都是非常實在的。

Each year, close to 500,000 people die due to excessive heat,

每年，將近 50 萬人死於高溫，

and these extreme conditions are only growing more common.

而這些極端氣候只會變得越來越普遍。

We can limit medical impacts by seeking help for heat-related illnesses,

為了限制對醫療體系的衝擊， 我們應該提供與熱相關的病症的支援，

staying hydrated,

攝取充足的水分，

and keeping people cool through public access to water and AC.

提供民眾公共的水源和冷氣空間。

But don’t let anyone tell you 1 to 2 degrees doesn’t matter.

但別讓任何人告訴你 1、2 度沒什麼大不了。

It will change our very way of life.

它將完全改變我們的生活方式。