“That rapid cooling after you get out of the shower or out of the bath tends to be a natural sleep inducer,” according to Christopher Winter, a fellow at the American Academy of Sleep Medicine and medical director at the Sleep Center at Martha Jefferson Hospital in Virginia. Much of the research has focused on baths but nevertheless, a 20-minute shower would have comparable effects.
Ideally, take a shower about an hour and a half before you turn in, as recommended by Shelby Harris. Utilizing this method will ensure that your body will be cool, dry and ready for sleep by the time you lay down.
An additional advantage is that you can kill two birds with one stone by washing your face, an important part of skin care, while you are showering. The National Sleep Foundation says that cleansing your face before bed can aid in keeping your skin clear and diminishing breakouts as well as guarding against wrinkles and supports moisturizers and night creams in being more effective.