You might feel itchy as you prepare for bed because of your circadian rhythms. More blood can flow to your skin, causing you to grow warmer. If you’ve been sweating, the perspiration may have dehydrated your skin. Finally, with little to occupy your mind as you drift off, you’re more likely to notice an itch. Bathing in cool or mildly warm water before bed can help you control nighttime itchiness. Other ways to minimize itching include: Wearing loose-fitting sleepwear. Using a fan to increase airflow.