(ALT 105.3) - You might already be trying to keep it cool at night during the summer as best you can, and if you are, it might not be great for your electric bill, but it looks like it's better for your health.
Per the Harvard Medical School, sleeping in a cold room will help you fall asleep faster. Your body is already trying to cool down right before sleep, so this helps to expedite that process, therefore putting you to sleep quicker.
What counts as a cold room? The U.S. National Institute of Health would consider 66 degrees and cooler is what constitutes "cold." They also say that sleeping in a room at that temperature will increase your metabolism and reduce the risk of metabolic illnesses.
Oh, and sleeping in a cold room can help reduce insomnia. Insomniacs have a higher body temperature when they're sleeping, and the University of Southern Australia deduced that a lower room temperature can help lead to a small temperature change in an insomniac's body, which is crucial to helping them drift off to sleep.