Avoiding caffeine, sticking to a schedule and drinking a glass of warm milk are the usual tips for a good night's rest. But the right room temperature can also play a crucial role.

    Studies have found that in general, the optimal temperature for sleep is quite cool, around 60 to 68 degrees Fahrenheit. For some, temperatures that fall too far below or above this range can lead to restlessness.

    Temperatures in this range, it seems, help facilitate the decrease in core body temperature that in turn initiates sleepiness. A growing number of studies are finding that temperature regulation plays a role in many cases of chronic insomnia. Researchers have shown, for example, that insomniacs tend to have a warmer core body temperature than normal sleepers just before bed, which leads to heightened arousal and a struggle to fall asleep as the body tries to reset its internal thermostat.

    For normal sleepers, the drop in core temperature is marked by an increase in temperature in the hands and feet, as the blood vessels dilate and the body radiates heat. Studies show that for troubled sleepers, a cool room and a hot-water bottle placed at the feet, which rapidly dilates blood vessels, can push the internal thermostat to a better setting.

    避免攝入咖啡因，作息規(guī)律，喝一杯溫牛奶，這些都是保證晚上休息好的小竅門。但是，合適的房間溫度也發(fā)揮著至關(guān)重要的作用。

    研究發(fā)現(xiàn)，一般情況下，睡眠的最佳溫度是很低的，大約在60-68華氏度范圍內(nèi)。對(duì)有些人來(lái)說(shuō)，溫度太過(guò)低于或高于這一范圍，可使其煩燥不安。

    溫度處于這個(gè)范圍內(nèi)，似乎利于中心體溫的降低，而中心體溫降低反過(guò)來(lái)利于睡眠。越來(lái)越多的研究表明，在許多習(xí)慣性失眠病例中，體溫調(diào)節(jié)發(fā)揮著作用。例如，研究人員發(fā)現(xiàn)，失眠癥患者臨睡前體溫比睡眠正常者高，這導(dǎo)致覺(jué)醒進(jìn)一步增強(qiáng)，并使得身體重新設(shè)置其內(nèi)部溫度控制器，進(jìn)入睡眠的難度加大。

    對(duì)睡眠正常者來(lái)說(shuō)，雙手和雙腳溫度的增加標(biāo)志著中心體溫降低，這是由于血管擴(kuò)張，身體輻射熱量之故。研究表明，對(duì)失眠者而言，涼爽的房間加上在腳旁放一個(gè)裝有熱水的瓶子可將身體內(nèi)部溫度控制器設(shè)置在較好的值上，而裝有熱水的瓶子可迅速擴(kuò)張血管。