Laundering bed linens often isn’t a top priority — most Americans change the sheets every three weeks. But if sleep with pets or have been ill, messy or “active,” strip the bed once a week. Every hour, your body sheds about 200 million skin cells, plus sweat, body oils, moisturizing lotions, and regular old dirt. Sheets and pillowcases should be laundered in the hottest water possible (check the care label) to thoroughly clean. Treat yourself to a good night’s sleep in a freshly-made bed.
From:: Bedding best practices.