Keep only one bed in the bedroom. Most important, encase box springs and mattress in a dust-proof or allergen-proof cover (zippered plastic). Scrub bed springs outside the room. If a second bed must be in the room, prepare it in the same manner. Keep all animals with fur or feathers out of the room. People allergic to dust mites often are allergic to cats, dogs, or other animals. Use only washable materials on the bed. Sheets, blankets, and other bedclothes should be washed frequently in water that is at least 130EF. Lower temperatures will not kill dust mites. If you set your hot water temperature to a lower value (which is commonly done to prevent children from scalding themselves), wash items at a commercial establishment that uses high wash temperatures. Keep furniture and furnishings to a minimum. Avoid upholstered furniture and venetian blinds. A wooden or metal chair that can be scrubbed may be used in the bedroom. If desired, hang plain, lightweight curtains on the windows. Wash the curtains once a week at 130EF. To prepare the room for a dust-sensitive person, clean the room thoroughly and completely once a week; clean the floors, furniture, tops of doors, window frames, sills, etc., with a damp cloth or oil mop; air the room thoroughly; then close the doors and windows until the dust-sensitive person is ready to occupy the room. Air filters--either added to a furnace or a room unit--can be useful in reducing the levels of allergens. Electrostatic and high-energy particulate absorption (HEPA) filters can effectively remove many allergens from the air. If functioning improperly, however, electrostatic filters may emit ozone, which adversely affects the lungs of people with asthma.