Many travelers face a common problem: jet lag.

许多旅行者面临一个共同的问题：时差。

It is the feeling of tiredness people get when traveling a long distance, resulting in a difference in daylight hours. Nobody wants to miss the fun because they are too tired to enjoy their vacation.

这是人们在长途旅行时感到的疲倦感，导致白天时间的差异。 没有人愿意因为太累而无法享受假期而错过乐趣。

Here are some tips on how to deal with jet lag:

以下是一些关于如何应对时差反应的提示：

Scientists define jet lag as the effect on the human body of traveling across time zones. Sofia Axelrod studies circadian rhythms at Rockefeller University in New York. She said a circadian rhythm is like a biological clock programmed into almost every cell in the body.

科学家将时差定义为跨越时区旅行对人体的影响。 索菲亚·阿克塞尔罗德在纽约洛克菲勒大学研究昼夜节律。 她说，昼夜节律就像一个生物钟，被编程到身体的几乎每个细胞中。

"The clock is set by the 24-hour light and dark pattern," Axelrod said. "Every morning when we wake up, specialized (light) receptor cells in our retina receive a daylight signal, which is transmitted to the brain and from there, (to) the whole body."

“时钟是根据 24 小时明暗模式设定的，”阿克塞尔罗德说。 “每天早上，当我们醒来时，视网膜中的特殊（光）受体细胞会接收日光信号，该信号被传输到大脑，并从那里传输到整个身体。”

When we travel to another time zone, our eyes do not receive the daylight signal at the usual time. This causes our “internal clocks” to reset. But that process can take a while. During that period, we feel the effects of jet lag.

当我们旅行到另一个时区时，我们的眼睛在平时接收不到日光信号。 这会导致我们的“内部时钟”重置。 但这个过程可能需要一段时间。 在此期间，我们会感受到时差的影响。

People who travel long distances often want to prevent jet lag. One way has a high cost.

长途旅行的人通常希望避免时差反应。 一种方法成本很高。

Malcolm von Schantz is a professor who specializes in circadian rhythms at Northumbria University in Newcastle, England. He said that paying a lot for a bigger seat and more space in an airplane can prevent sleep deprivation.

马尔科姆·冯·尚茨 (Malcolm von Schantz) 是英国纽卡斯尔诺森比亚大学的一名教授，专门研究昼夜节律。 他说，花很多钱购买更大的座位和更大的飞机空间可以防止睡眠不足。

He knows most people cannot pay so much to travel. But he said timing your flights can help. For example, he suggests flying from Europe to North America during the day, so that it is evening when passengers land and they can get to sleep.

他知道大多数人无法花这么多钱去旅行。 但他说，安排航班时间会有所帮助。 例如，他建议白天从欧洲飞往北美，这样乘客落地就是晚上，可以入睡。

"If you take the evening flight instead, you'll be woken up at midnight to be served breakfast and land an hour or two later, when both jet lag and sleep deprivation will hit you hard," he said.

“如果你乘坐晚上的航班，你会在半夜被叫醒吃早餐，并在一两个小时后着陆，此时时差和睡眠不足都会对你造成严重打击，”他说。

Von Schantz also said flying in newer model passenger jets, like the Airbus A350 or Boeing 787 Dreamliner, might help. He said those planes can maintain a more comfortable atmosphere inside, causing less tiredness.

Von Schantz 还表示，乘坐空客 A350 或波音 787 梦想飞机等新型客机可能会有所帮助。 他说，这些飞机可以保持机内更舒适的氛围，减少疲劳。

Experts say being in sunlight is important to resetting your internal body clock. That could mean either avoiding morning sun or seeking it out, depending on where you started.

专家表示，沐浴在阳光下对于重置体内生物钟非常重要。 这可能意味着要么避免早晨的阳光，要么寻找阳光，这取决于你从哪里开始。

Getting light in the morning will move your body clock forward, while light exposure in the early evening will delay it. Sleeping for a short time during the day is acceptable, but scientists warn against sleeping for longer periods later in the day. Doing so might make it harder to sleep through the night.

早上接受光照会使你的生物钟提前，而傍晚的光照会推迟它。 白天睡一小段时间是可以接受的，但科学家警告不要在当天晚些时候睡更长的时间。 这样做可能会让整晚更难入睡。

The brain naturally produces a chemical hormone called melatonin when the body thinks it is night. Taking melatonin as a supplement can be helpful. But it is not available everywhere and, in some countries like Britain and France, you need a doctor’s permission.

当身体认为是晚上时，大脑会自然产生一种称为褪黑激素的化学激素。 服用褪黑激素作为补充剂可能会有所帮助。 但它并非在所有地方都可用，在英国和法国等一些国家，您需要医生的许可。

Von Schantz said that one of the good effects of melatonin is that you can start taking it before you travel, to begin the process of resetting your internal clock.

冯·尚茨说，褪黑激素的好处之一是您可以在旅行前开始服用它，以开始重置您的生物钟的过程。

"If you're in a part of the world where melatonin is available over the counter, you can combine the effects of light and melatonin to achieve the advan