Many sleep experts say that a cool room, somewhere around 65 degrees, makes for the best sleep, and research backs this notion.
During the course of a normal day, your body temperature rises and falls slightly. This pattern is tied to your sleep cycle. As you become drowsy, your temperature goes down, reaches its lowest level around 5:00 a.m., and climbs slightly as morning begins. This is why the air in your room can affect the quality of your sleep: if it’s too hot, it may interfere with your body’s natural dip and make you more restless through the night. In fact, studies indicate that some forms of insomnia are associated with an improper regulation in body temperature. Of course each of us has a slightly different optimal temperature for sleep, so experiment with keeping your room cool and find what makes you most comfortable.