自打入伏以來，國內多地就開啟了桑拿模式，氣溫直逼40度。吃冰棍喝冷飲，還是喝熱茶，哪一種才是降暑的正確打開方法？

While you might be tempted to reach for a cold drink to help cool you down in such hot weather, surprisingly hot drinks such as teas and coffees may actually be more effective.

在這種大熱天，你或許非常想喝杯冷飲來涼快一下，但讓人驚訝的是，茶和咖啡等熱飲可能對解暑更有效。

A study in 2012 by researchers from the University of Ottawa looked at the effect of drinking hot drinks on body temperature.

渥太華大學的科學家在2012年研究了喝熱飲對于減少體溫的成效。

The results revealed that a hot drink can cool you down, but only in dry conditions.

研究結果揭示，熱飲可以叫你感覺涼快，但只有在干燥的環境中才這樣。

Speaking to the Smithsonian Mag, Dr Ollie Jay, one of the authors of the study, explained: “If you drink a hot drink, it does result in a lower amount of heat stored inside your body, provided the additional sweat that’s produced when you drink the hot drink can evaporate.”

在同意《史密森掌握雜志》采訪時，該研究的作者之一奧利·杰博士講解說：“假如喝熱飲，體內儲存的熱量就會減少，首要條件是喝熱茶時排出的汗水可以蒸發掉。”

Essentially, when you ingest a hot drink, you start sweating more. If the sweat is able to evaporate, it actually cools you down, more than compensating for the added heat to the body from the fluid.

基本原理是，當你喝熱飲時，你會流更多汗，假如汗水可以蒸發掉，你就會感到涼爽，這個過程中減少的體溫超越了熱飲給你增加的體溫。

While sweating can be embarrassing, it’s an essential body function to help keep us cool.

盡管流汗讓人尷尬，但卻是人體的一項要緊功能，能夠幫助維持涼爽。

As the sweat evaporates from the surface of your skin, it removes excess heat by converting the water from a liquid to a vapour.

當汗水從皮膚表面蒸發時，會在水轉化為蒸汽的過程中帶走多余的熱量。

However, in humid conditions this cooling effect is less effective, so drinking hot drinks won’t help to cool you down.

但，在潮濕的環境中，這種降溫成效就沒那樣明顯，因此在潮濕天氣喝熱飲也就不可以幫你解暑。

Dr Jay explained: “On a very hot and humid day, if you’re wearing a lot of clothing, or if you’re havin so much sweat that it starts to drip on the ground and doesn’t evaporate from the skin’s surface, then drinking a hot drink is a bad thing.

杰博士講解說：“在悶熱潮濕的天氣，假如你穿著不少衣服，或者你汗如雨下，而且沒從皮膚表面蒸發掉，那樣喝熱飲就不利于解暑。”

The hot drink still does add a little heat to the body, so if the sweat’s not going to assist in evaporation, go for a cold drink.”

“熱飲仍然會給身體增加一點熱量，所以假如汗水沒辦法蒸發，那就選擇冷飲。”

Overall, the lesson learned is that in hot, dry conditions, drinking hot drinks will cool you down, but if you’re in a humid location, it’s best to stick to cold beverages.

總體而言，大家得到的結論是，在炎熱干燥的天氣里，喝熱飲會叫你感覺涼爽，但假如天氣潮濕，最好還是喝冷飲。