8. Balances your melatonin and growth hormone.
Continuing along that same vein, keeping your sleeping environment below 70 degrees (F) every night can help your body regulate its melatonin and growth hormone levels. These chemicals help the body do things like prevent aging and are essential to good health. When you sleep in clothes, your body heats up and prevents effective use of these hormones. In other words, sleeping with clothes on makes you grow old faster.