如何在夏天保持涼爽
Summer is coming. 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.
酷夏即將來臨。當最熱的時候到來時，在室外的每一秒都像是桑拿屋裏的脫水之旅。但是別緊張，總有讓你不用便攜空調也能保持身體涼爽的方法。
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.
科學家第一次研究天氣對人體舒適度的影響是在20世紀60年代。差不多在同時期，空調的發明讓我們可以隨意調節辦公樓和家裏的溫度。一位名叫伯維爾·歐樂·範格的科學家提出了一個舒適度方程，方程要考慮的變量包括溫度、溼度、氣流速度、穿着和活動量。他的這個方程幫我們更好地瞭解人體自我降溫的原理，以及如何在最熱的天氣裏保持涼爽的。
Wear loose clothing, mostly cotton
穿棉質寬鬆的衣服
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，寬鬆的衣服可以使空氣在皮膚上流動。這樣（寬鬆的衣服）可以帶走你身體產生的熱量，也可以讓涼爽的空氣流入進來。緊身牛仔褲和緊身夾克之類的衣服會把熱氣禁錮在你皮膚上，會讓你覺得更熱。另外，像是寬鬆的褲子、飄逸的襯衫或裙子等等不那麼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。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，因爲空氣可以穿過面料本身。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節體溫。下丘腦的工作原理和家中的恆溫器相似，根據不同的因素來調高或降低體溫，比如說，根據皮膚溫度的冷熱。
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爲在這些地方可以感受到脈搏，而且因爲這裏的血管和皮膚最近，人們可以輕易地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.
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降低身體“恆溫器”的溫度。你可以從幾個方便的脈搏點着手：手腕的內側、太陽穴附近的區域還有頸部的區域。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.
通常不推薦在酷熱的天氣裏鍛鍊。因爲運動會使人體體溫進一步升高並且會導致出汗，這兩樣都不會讓人感覺太舒服。人大量出汗時，還會增加脫水的風險。所以在室外特別炎熱的時候，確保不要運動得太厲害。
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，這是我們身體調節體溫的最佳方式。出汗可以使皮膚溫度下降，這樣也會讓我們覺得很涼爽。而且當人體水分充足時，也是調節體溫最容易的時候。
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.
適當的水分可以調節血流，反過來也能決定皮膚的溫度。而且這還能告知作爲“恆溫器”的下丘腦如何來調節人體的內部溫度。
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，你已經脫水了。所以，爲了避免脫水和它帶來的負面影響，我們應該在一天中定時補充水分，而且要在感覺到口渴之前就喝水。
