为什么睡觉前要洗澡?

At this point, we're pretty sure if someone paid us to stand under a jet of hot water all day and think about its health benefits, we'd forego the money and do it for free. Studies have already shown that showers can awaken your mind and boost creativity, but research is supporting the idea that a hot shower before bed can also help you fall asleep. Dr. Dianna Augelli of the Center for Sleep Medicine at NewYork-Presbyterian/Weill Cornell Medical Center has applied studies that support pre-bedtime baths to showering habits as well. There's some finesse to it, but the bottom line is: Hop in the shower before bed. It'll help your body cool down and relax.
在这一点上，我很确定，如果有人付钱给你，让你整天站在热水下，想想这样做的健康好处，我们会不收取钱财，免费去做的。研究已经证明淋浴可以唤醒我们的大脑、提高创造力，但研究支持这样的想法：睡前洗个热水澡有助于睡眠。纽约教会医院/威尔康奈尔医学中心睡眠医学中心的戴安娜·奥吉利已将支持睡前洗澡的研究应用到了洗澡习惯上。这肯定是有技巧的，但最起码要在睡觉前洗个澡。因为睡前洗个热水澡有利于放松身心。

Key to the whole game is timing. "You don't want to heat yourself up right before bed," Dr. Augelli told TIME Health. "Cooling down is a signal that tells us we're supposed to go to sleep."
而整个游戏中，最关键的一点在于时间。"入睡前，你并不想感到燥热吧，"奥吉利博士在接受TIME Health的访问时说道。"降温给身体发出了信号：是时候睡觉了。"

The optimal timing? Ninety minutes before you want to hit the hay. By then, your body can regulate its circadian rhythms-essentially the signals that tell it when to feel alert and when to feel sleepy. Right after the shower, you'll heat up and feel more alert and active and possibly creative, but as time passes and you begin the cool-down process, your system will feel more primed for rest instead of still feeling warmer and antsier. Plus, you'll be dry after 90 minutes-no damp pillow.
最优时间？睡觉前90分钟洗个澡。到那时，你的身体能调节昼夜节奏--基本上就是什么时候该清醒，什么时候该睡觉。洗完澡后，你会浑身发热，会感到更精神、更有活力、甚至可能更有创造力，但随着时间的流逝，身体开始降温，人体系统更想要休息，而不是感觉更暖、更坐立不安。另外，90分钟后你的头发肯定干了--枕头就不会潮了。

You stay in the shower too long.
洗澡时间太久。

Not only can staying in the shower too long dry out your skin, it's also a tremendous waste of water. According to the Alliance for Water Efficiency, the average shower in America uses 17.2 gallons of water. Shorten your daily shower to 5 minutes, and you'll save more than 2,000 gallons of water each year.
洗澡时间太久不仅会使肌肤干燥，而且还严重浪费水资源。据水效联盟（Alliance for Water Efficiency）所述，美国人洗澡的平均用水量为17.2加仑。每天洗澡不要超过5分钟，那每年你就能节省2000加仑的水。

You wash your hair last.
最后才洗头。

Shampooing and conditioning your hair should be among the first steps you take when you get in the shower. Some of the residue from these hair products can remain on your face, skin, and hair even after rinsing, so it makes sense to follow hair washing with the rest of your shower routine.
洗澡的第一步应该是洗头、上护发素。即使冲干净后，护发产品的残留物也有可能停留在脸上、肌肤上、头发上，所以洗澡先洗头是有道理的。