老生常談:夏天到了，怎樣讓自己過的涼爽些？

Summer is coming. And many parts of the country have already experienced days that encroach on that line between a lovely spring evening and one that’s so uncomfortably hot it makes you want to stand under a cold shower. When those days come, every second you spend outside feels like a dehydrating walk through the sauna. But don’t sweat. There are ways to cool your body down without resorting to a portable AC unit.

夏天就要到了。美國很多地方最近幾天的經(jīng)歷正在蠶食涼爽春夜和熱到想洗涼水澡之間的最后一道防線。等到夏天到來之后，在室外的每一秒都像是在桑拿屋里的脫水之旅。但是別緊張，總有讓你不用便攜空調(diào)也能讓你身體涼爽的方法。

Scientists first started studying how weather contributes to human comfort in the 1960s. That’s around the time when the invention of air conditioning finally let us control the temperatures of office buildings and homes. A scientist named Povl Ole Fanger came up with an equation called the comfort equation, which took into account a variety of different variables, including temperature, humidity, air velocity, clothing resistance, and activity level. His equation has also helped us better understand how the human body cools itself—and how to stay chill even on the hottest of days. Here’s what we’ve learned.

科學(xué)家第一次研究氣候?qū)θ梭w舒適度的影響是在20世紀(jì)60年代。差不多在同時期，空調(diào)的發(fā)明讓我們可以隨意調(diào)節(jié)辦公樓和家里的溫度。一位名叫Povl Ole Fanger的科學(xué)家提出了一個舒適度方程，方程中要考慮到種種變量，包括溫度、濕度、氣流速度、穿著和活動量。他的這個方程幫我們更好的了解人體是如何自我調(diào)節(jié)溫度，還有如何在最熱的天氣里保持涼爽的。以下就是我們所學(xué)到的。

Wear loose clothing, mostly cotton

穿棉質(zhì)寬松的衣服

This seems obvious, but wearing clothing that is loose rather than tight allows air to flow past the skin. This carries away the warmth that your body generates and allows cooler air to flow back in. Clothes like tight jeans or a snug jacket trap that heat against your skin, which just makes you feel hotter. On the other hand, less fitted clothes like loose pants, a flowy shirt, or a dress all allow air to keep circulating

這一條似乎顯而易見，比起穿緊身的衣服，寬松的衣服可以使空氣在皮膚上流動。這樣(寬松的衣服)可以帶走你身體產(chǎn)生的熱量，也可以讓涼爽的空氣流入進(jìn)來。像是緊身牛仔褲和緊身夾克會把溫度禁錮在你皮膚上，會讓你覺得更熱。另外，像是寬松的褲子、飄逸的襯衫或裙子等等不那么緊身的衣物可以保持空氣的流通。

The type of fabric you wear has an influence, too. When it’s really hot out, materials that “breathe”—allowing the flow of air through the fabric itself—also work to keep you cool. Cotton and linen are among the most breathable fabrics, so look for clothes made of those substances, as opposed to less permeable synthetics.

衣物的面料也是有影響的。當(dāng)室外十分炎熱的時候，可以“呼吸”的面料也能讓你感到更涼爽，因為空氣可以穿過面料本身。純棉和亞麻是最透氣的面料，所以多穿這些面料的衣物，少穿透氣性差的人造纖維面料。

Apply cold packs strategically

巧用冷敷袋

Your body regulates its temperature via a small peanut-shaped section of the brain known as the hypothalamus. This region works almost like a thermostat in a home, turning the temperature up or down based on various factors—such as how cold or hot the skin is.

人的身體通過腦部花生大小的下丘腦來調(diào)節(jié)體溫。下丘腦的工作原理和家中的恒溫器相似，根據(jù)不同的因素來調(diào)整升高或降低體溫，比如說根據(jù)皮膚溫度的冷熱。

Certain parts of the skin have a larger influence than others. These areas are called pulse points. They get their name because you can feel your pulse there, and the reason you can do that is because vessels are so close to the edge of your skin that one can easily hear or feel the flow of blood.

有些特定部位的皮膚對下丘腦的影響比其他部位更顯著，這些位置就是脈搏點。之所以叫脈搏點是因為在這些地方可以感受到脈搏，而且因為這里的血管和皮膚最近，人們可以輕易的聽到或感觸到血液的流動。

When you want to lower your body temperature, chilling those pulse points with cold water or ice sends a signal to the brain that says, “I’m cold.” This tricks your brain into turning down its thermostat. Focus on pulse points that are easy to reach: the insides of your wrists, the area around your temple, and your neck. Holding an ice pack or even a cold washcloth against the skin on these regions will make your entire body feel cooler.

當(dāng)你想降低體溫時，用冷水或者冰塊冷敷這些脈搏點會向大腦傳遞一個信號——“我好冷”。這樣做可以欺騙大腦讓它關(guān)掉“恒溫器”。有幾個主要又方便的脈搏點：手腕的內(nèi)側(cè)、太陽穴附近的區(qū)域還有頸部的區(qū)域。用一個冷敷袋或是一塊涼毛巾放在這些地方的皮膚上會讓你整個人都感覺涼快一些。

Count your steps

少運動

Exercising in extreme heat is usually not recommended. That’s because exercise actually heats the body up further and causes you to sweat, both of which make you feel more uncomfortable. When you’re sweating more, you’re also at greater risk of dehydration. So when it’s terribly hot outside, make sure you don’t exercise too much.

通常不推薦在極炎的天氣里鍛煉。這是因為運動會使人體體溫進(jìn)一步升高并且會導(dǎo)致出汗，這兩樣都不會讓人感覺太舒服。當(dāng)人大量出汗時，還會增加脫水的風(fēng)險。所以在室外特別炎熱的時候，確保不要運動的太厲害。

Hydrate

補充水分

Speaking of sweat, that’s the best method our bodies have evolved to regulate body temperatures. Sweating helps to cool off the skin, which keeps the rest of us cool. And the human body can regulate itself far more easily when it’s fully hydrated.

談到出汗，這是我們身體調(diào)節(jié)體溫的最佳方式。出汗可以使皮膚溫度下降，這樣也會讓我們覺得很涼爽。而且當(dāng)人體水分充足時，也是調(diào)節(jié)體溫最容易的時候。

Proper hydration regulates blood flow, which, in turn, helps to determine the temperature of the skin. That then tells our master thermostat, the hypothalamus, how to regulate our internal temperature.

適當(dāng)?shù)乃挚梢哉{(diào)節(jié)血流，反過來也能決定皮膚的溫度。而且這還能告知作為“恒溫器”的下丘腦如何來調(diào)節(jié)人體的內(nèi)部溫度。

The sad part is that, by the time you feel thirsty, you are already dehydrated. So, to prevent dehydration and its negative effects, you should be drinking water throughout the day on a regular basis—even before you feel thirst.

悲劇的是，等你感覺到口渴的時候，你已經(jīng)脫水了。所以，為了避免脫水和它帶來的負(fù)面影響，我們應(yīng)該在一天中定時補充水分，而且要在感覺到口渴之前。