Whenever your body temperature begins to fall, you will feel tired, lethargic, and drowsy. Whenever your body temperature rises, you will feel more energetic, alert and be able to focus better. This is why hot summer nights can make it so difficult to sleep.
Since the mild drop in body temperature tends to induce sleep, sleeping in a cooler environment makes that drop in body temperature happen easier.
In general, the ideal temperature for sleeping is between 60 to 68°. Whenever the room becomes uncomfortably hot or cold, you are more likely to wake up. You may want to experiment with your bedroom temperature to see what is ideal for you. This is one strategy for insuring a healthy sleep environment.
module 4 page 4 of 11