Washing pillowcases in hot water once a week is important for health reasons. According to Business Insider, bacteria and up to 16 different fungal species accumulate in the tissue. In turn, they can cause or worsen acne, asthma, allergies, and other potentially serious health conditions. People who suffer from these conditions should wash their pillowcases more frequently, perhaps as often as every two or three days, says Piles of Pillows.
When shopping for bedding, choose a fabric for its comfort, but also consider its hygiene and cleaning characteristics. Cotton, the most popular, is easy to care for and comes in a variety of textures. It does, however, collect oils and debris, so it is important to follow maintenance instructions correctly. Cotton blends are also common, affordable and easy to care for. Other popular fabrics, according to Piles of Pillows, are satin, silk, linen, and nylon. Washing pillowcases more often than the accompanying sheets may cause color differences. To avoid this problem, buy additional matching pillowcases and rotate them so that each is washed less frequently.
In addition to the fabric, other factors include the weather in your area, your activity level and the amount of sweat you sweat. Also consider whether you shower before bed, what facial and hair care products you use, time spent outdoors, and pets, especially pets allowed on the bed.