How Much Water Should You Drink When It’s Hot Outside?炎熱天氣下該喝多少水？

Record-setting high temperatures are dangerous not only for the planet， but also for human health. Whether you’re situated in the middle of a heat wave or you’re just trying to survive a scorching day， you’ll need strategies to cool off and stay well.

創紀錄的高溫不僅危害地球，也無益于人類健康。無論你正身處熱浪之中，還是只想熬過酷熱難耐的一天，都需要了解幾條降溫策略以保持健康。

One of the most crucial is to stay hydrated. But do eight eight-ounce1 glasses really cut it2 amid skyrocketing temps？

最關鍵的策略之一是保持身體水分充足。但是，隨著氣溫飆升，喝下8杯每杯8盎司的水真的足夠嗎？

What you need on a normal day—and a scorcher

平日與酷熱天氣下的飲水需求

Most adults should drink somewhere between 68 and 100 ounces of water each day， says Dr. Ashley Karpinos， associate professor of medicine， pediatrics， and sports medicine at Vanderbilt University Medical Center. Another way to keep track of your water intake is to halve your weight in pounds—then drink that number of ounces each day， says Dr. Dana Cohen， an integrative medicine practitioner in New York City and co-author of Quench， a book about the science behind hydration.

范德比爾特大學醫學中心的醫學、兒科學及運動醫學副教授阿什莉·卡皮諾斯博士表示，大多數成年人每天應攝入68到100盎司（約2到3升）的水。紐約市綜合醫學執業醫師、《解渴》（一本關于補水科學的著作）合著者達娜·科恩博士提供了另一種飲水計算方式：將體重磅數除以2，然后每天飲用對應數值盎司的水。

But “in the heat， everyone needs more water，” Karpinos says. If you’re working， exercising， or are otherwise active in hot weather， a good rule of thumb is to drink eight ounces of water every 15 to 20 minutes during the physical parts of your day， Karpinos says.

但卡皮諾斯表示：“天氣炎熱時，每個人都需要更多的水。”她指出，如果你在高溫天氣下工作、運動或從事其他活動，一個實用的法則是：在體力活動時段內，每15到20分鐘飲用8盎司水。

Seems simple， right？ Not so much. Hydration is complex. Not only do some people need more water than others， but sometimes， a glass of H2O isn’t even the best solution. The following tips from experts can help ensure you’re properly hydrated when it’s hot outside.

看似簡單，對吧？并非如此。補水很復雜。不僅有些人比其他人需要更多的水，而且有時候，一杯純水甚至并非最佳選擇。以下這些來自專家的建議可以確保你在天氣炎熱時恰當補水。

Monitor your bathroom breaks

留意如廁頻率

The best way to keep track of how hydrated you are in hot weather isn’t through the total ounces of water you drink， but rather how often you’re urinating， Cohen says. “If you’re not getting up and going to the bathroom every two or three hours， you’re not well-hydrated，” she says. “That is truly the best way to do it—not looking at your urine color， not pinching your skin.”

科恩指出，在炎熱天氣下，判斷身體水分是否充足的最佳方法，不是看你總共喝了多少盎司的水，而是看你的排尿頻率。“如果你不是每兩三小時就起身去趟洗手間，就說明你水分補充得不夠。”她說，“那實際上是最合適的判斷方法——既不是看尿液顏色，也不是掐皮膚。”

Think beyond water

不限于水

Water is typically the best thing you can drink when it’s hot outside， Karpinos says. But other beverages can also do an excellent job keeping you hydrated. She recommends drinking something with electrolytes3 after about an hour in the heat. Sports drinks like Gatorade will do the trick， but Cohen recommends coconut water， as it contains natural electrolytes.

卡皮諾斯指出，通常來說，在炎熱天氣下，水是最佳飲品。但其他飲料同樣能有效補充水分。她建議，在炎熱環境下待大約1小時后，飲用含電解質的飲品。像佳得樂這樣的運動飲料就能奏效，但科恩推薦飲用椰子水，因為后者含有天然電解質。

Some research suggests a surprising drink might be hydrating as well： milk. One small 2016 study published in the American Journal of Clinical Nutrition gave people 13 beverages and tested their urine output over the next four hours. All of the beverages tested （including still and sparkling water4， soda5， diet soda， hot and iced tea， beer， orange juice， coffee， a sports drink， skim and full-fat milk， and an oral rehydration solution） had more or less the same hydrating effect except for three standouts： the oral rehydration solution， full-fat milk， and skim milk. Cow’s milk has sodium and electrolytes， which could potentially stave off6 dehydration.

有研究顯示，一種意想不到的飲料或許也有助于補水：那就是牛奶。發表于《美國臨床營養學雜志》的2016年的一項小型研究中，研究人員讓受試者飲用13種飲料，并檢測他們接下來4小時內的排尿量。結果顯示，所有參與測試的飲料（包括無氣泡水、氣泡水、汽水、無糖汽水、熱茶、冰茶、啤酒、橙汁、咖啡、運動飲料、脫脂牛奶、全脂牛奶，以及口服補液鹽溶液）在補水效果上大致相同，但有3種飲品表現突出：口服補液鹽溶液、全脂牛奶和脫脂牛奶。牛奶含有鈉和電解質，或能避免脫水。

Skip the Aperol spritz and iced coffee

放下阿佩羅橙光雞尾酒和冰咖啡

Generally speaking， any fluid is good for hydration except for drinks with caffeine and alcohol since both are diuretics7， says Lina Begdache， a registered dietitian and associate professor at Binghamton University’s Decker College of Nursing and Health Sciences. It’s also important to avoid alcohol in the heat because it can interfere with the body’s ability to regulate its core temperature， says Dr. Seth Feltheimer， a primary care physician and associate professor of medicine at Columbia University Vagelos College of Physicians and Surgeons.

注冊營養師、賓厄姆頓大學德克爾護理與健康科學學院副教授莉娜·貝格達什表示，一般而言，任何液體都有助于補充水分，但含有咖啡因和酒精的飲料除外，因為兩者都有利尿效果。基礎醫療醫師、哥倫比亞大學瓦格洛斯內科和外科醫師學院醫學副教授塞思·費爾特海默博士說，在炎熱天氣中避免飲酒也很重要，因為酒精會干擾人體調節體核溫度的能力。

Cohen notes that coffee is only problematic in excess. “Anything over four cups of coffee， and it starts to become a diuretic，” she says.

科恩指出，咖啡只有在過量飲用時才有問題。她說：“飲用咖啡超過4杯，利尿作用就會開始顯現。”

Add water-rich foods to your diet

將富含水分的食物納入日常飲食

Eating foods with a high water content is a great way to stay hydrated in the heat， Karpinos says. She recommends fruits and vegetables like watermelon， cantaloupe， berries， peppers， lettuce， and cucumbers. “You can also add mint leaves or fresh orange slices to flavor your water， which can make it easier to drink enough.”

卡皮諾斯指出，高溫天氣，食用含水量高的食物是保持身體水分充足的絕好方法。她推薦西瓜、網紋甜瓜、漿果、甜椒、生菜和黃瓜這樣的蔬果。她補充道：“你還可以在水中加入薄荷葉或新鮮橙片來調味，這樣能讓你更容易喝夠水。”

Cohen also recommends smoothies8， as well as chia seeds and flax seeds because of their high fiber content.

科恩還推薦思慕雪，以及奇亞籽和亞麻籽，因為后兩者富含纖維。

Hydrate before you feel thirsty

不要等到口渴才喝水

One of the biggest mistakes people make is waiting until they feel thirsty to drink water， Karpinos says. This is because by the time you feel thirsty， you’ve already lost fluid and you’re on the way to dehydration.

卡皮諾斯指出，人們所犯的最大錯誤之一就是等到口渴時才喝水。這是因為，當你感到口渴時，你已經流失了體液，即將脫水。

Begdache adds that it’s also good to drink water before bed and first thing in the morning since you lose water while you sleep to respiration and sweating.

貝格達什補充道，睡前和早晨醒來后喝水也有好處，因為睡眠期間身體會通過呼吸和出汗而流失水分。

Pay special attention to children and the elderly

特別關注兒童和老人

Since children are smaller than adults， their stores of water are also smaller and they’re more likely to get dehydrated in hot weather， Feltheimer says. The amount of water children need varies—toddlers need about 32 ounces a day， while pre-teens need about 60 ounces， Karpinos says. “Watch children closely for facial flushing， fussiness， or less urination， which can be signs of dehydration，” she says.

費爾特海默指出，由于兒童的體型比成人小，他們身體儲存的水分也更少，因此在炎熱天氣下更容易脫水。卡皮諾斯表示，兒童需要的水分因年齡而異，學步階段的兒童每天需要約32盎司水，而10歲出頭的兒童每天需要約60盎司水。她說：“要密切留意兒童是否出現面部潮紅、哭鬧不安或排尿減少的情況，這些可能是脫水的跡象。”

Elderly people are more likely to become dehydrated as well. This is because the body’s water content decreases with age. One 2023 study published in the International Journal of Clinical and Laboratory Medicine looked at hydration status9 in nearly 1，000 elderly adults. Researchers found that 31% of participants were dehydrated. Diabetes and chronic renal failure were more common in the dehydrated group， as was their likelihood of experiencing a fall.

老年人同樣更容易脫水。這是因為隨著年齡增長，身體的含水量會逐漸減少。《國際臨床與實驗醫學雜志》發表過2023年的一項研究，該研究調查了近1000名老年人的水合狀態。研究人員發現，31%的參與者存在脫水問題。而在脫水組中，糖尿病和慢性腎功能衰竭更為常見，他們發生跌倒的可能性也更高。

Be on the lookout for dehydration

警惕脫水

Early signs of dehydration include feeling thirsty， having dry lips and mouth， not sweating enough， and dark urine， Karpinos says. Feltheimer adds that body cramps， lethargy， and an inability to urinate “are all signs that your body is trying to conserve whatever fluid it has.”

卡皮諾斯表示，脫水的早期跡象包括口渴、唇干口燥、出汗不足及尿色深。費爾特海默補充道，身體抽筋、乏力及排尿困難“都是身體在盡力保存體內剩余水分的表現”。

Being dehydrated can have a greater impact than many people realize. Even just a 2% drop in hydration can lead to brain fog， headaches， and dizziness， Cohen says. One 2019 study found dehydration can also have a negative effect on short-term memory， attention， energy， and mood.

脫水的影響可能比許多人意識到的更嚴重。科恩表示，即使身體水分減少僅2%，也可能導致腦霧、頭痛和頭暈。2019年的一項研究發現，脫水還會對短期記憶力、注意力、精力和情緒產生負面影響。

Drinking enough water is also important long-term. One 2023 study published in the Lancet found chronic dehydration can lead to premature aging， chronic disease （including heart failure， diabetes， and dementia）， and premature death.

從長遠來看，攝取足夠的水分同樣至關重要。《柳葉刀》發表過2023年一項研究的報告，該研究表明，長期脫水可能導致早衰、慢性疾病（包括心力衰竭、糖尿病和癡呆）以及過早死亡。

Don’t overhydrate

避免過度補水

Some people—in an attempt to stay hydrated on hot summer days—overdo it. Cohen says she regularly sees patients with lab results that are too low in sodium and chloride because they’re drinking too much water. Overhydration， she says， can lead to many of the same symptoms as dehydration， like muscle cramps and fatigue.

一些人為了在炎夏保持身體水分充足而拼命喝水，結果卻飲水過量。科恩說，她經常接診因飲水過多導致鈉和氯檢測值過低的病人。她指出，過度補水可能引發許多與脫水相同的癥狀，比如肌肉痙攣和疲勞。

Although a little extra water is nothing to worry about， drinking way too much can lead to hyponatremia， a condition caused by not enough sodium in the blood that can lead to seizures10. Cohen notes that overhydrating to this level is exceptionally rare， but it’s still something to be aware of.

盡管稍稍多喝水無需擔憂，但喝得太多可能導致低鈉血癥；這是一種因血液中鈉含量不足引發的病癥，可能導致暈厥。科恩指出，達到這種程度的過度補水極其罕見，但仍需警惕。

（譯者單位：西安外國語大學）

1 ounce盎司，英美制質量或重量單位。1美制液盎司=29.57353毫升，8杯每杯8盎司的水總計約1.9升。" 2 cut it〈主美式口語〉達到要求。

3 electrolyte電解質，對維持人體正常生命活動起重要作用。" 4 still water無氣泡水，指不含二氧化碳氣泡的飲用水，與“氣泡水”（sparkling water）相對，可以是純凈水、非充氣型的礦泉水或泉水等。" 5 soda含糖碳酸飲料（如可樂或雪碧），與中文中的“蘇打水”（通常指含碳酸氫鈉的水）有所不同，后者可譯為baking soda water。" 6 stave off延緩、阻止或避免（某事的發生，通常指不好的或令人不適的事情）。

7 diuretic利尿劑。

8 smoothie思慕雪，一種用水果、蔬菜、酸奶或牛奶等制成的果昔。

9 hydration status〔醫學〕水合狀態，指機體水的攝入和排出的平衡情況。

10 seizure〔神經病學〕突發并持續一段時間后迅速恢復正常的神經系統癥狀，如暈厥或癲癇發作。