How often should you wash your bedding? Not many know exactly how often they should, and many an uninformed bachelor will not wash them for months if not years at a time. A good rule of thumb is to have them washed at least once every two weeks. If you sweat at night then you should be washing once a week. Remember to wash all bedding in water that is at least 130 degrees Fahrenheit to kill the dust mites. If you are getting over a cold than increase the temperature to between 140 and 150 degrees Fahrenheit to kill the virus and germs.