大热天喝热饮有助散热?

Does Drinking Something Hot On A Hot Day Cool You Down?

大热天喝热饮有助散热？

One common factoid that has been circulating the internet recently is that drinking a hot beverage on a hot day will cool you down. Some immediately dismiss the claim while others swear by it.

最近网上疯传在热天喝热饮能散热的言论。对此，有些人立马表示否定，而另一些人则表示强烈支持。

But who is right? Is there any actual scientific evidence behind this seemingly counter-intuitive claim?

究竟哪一方是对的呢？这个看似反常理的言论究竟有无科学依据？

Drinking something hot on a hot day can indeed cool you down, but there is a catch. A study done at the University of Ottawa's School of Human Kinetics showed that if you were to drink a hot beverage in a hot and dry environment, your body will overcompensate for the added heat by sweating, and sweating a lot. It's this excessive sweating that causes your body to cool down, and cooling it down more than if you had drank something cold instead.

热天喝热饮的确能降温，但这也是有条件的。渥太华大学人类动力学院曾做过相关实验，结果表明，如果在炎热干燥的环境下喝热饮，身体会通过流汗代谢多余热量。这些多排出的汗会让你身体凉爽下来，比喝冷饮效果要好。

However, this cooling effect only works if the air is dry, rather than humid. You cannot sweat efficiently enough to take advantage of the benefit in a muggy or humid environment.

但这个冷却效果只在干燥空气下才有用。在闷热潮湿环境下完全不管用。

You may have already experienced this effect when eating hot or spicy foods. Research at the University of Cambridge discovered that one specific receptor, the TRPV1 receptor, was responsible for sensing heat and telling our body how to respond. In many individuals, the response is to produce excessive sweat.

吃很辣或者很烫的食物也会有此效果。剑桥大学的实验表明，人体有种叫trpv1的受体，主要负责感知热力，并且告诉你的身体如何反应。大多数人的反应都是流汗。

If the air around you is dry and you're wearing light clothes, eating foods spicy enough to cause a sweating reaction will also produce the same cooling effect as drinking a hot beverage.

如果周遭环境干燥，你又穿着很薄的衣服，吃辣的食物会引发流汗，跟喝热饮的效果一样。

So to recap, this myth isn't a myth at all. Drinking something hot can in fact cool you down if the right conditions are met.

综上所述，这个说法其实符合常理。如果条件合适，喝热饮的确能给身体降温。

译文属原创，仅供学习和交流使用，未经许可，请勿转载。