A heated mattress pad contains carbon fiber wires which are as thin as possible to increase comfort. Add this mattress pad to your bed and you have an instant heated mattress. As a mattress pad, it comes with a skirt to attach to the mattress as well as a soft fill of either cotton or polyester. Also called an electric mattress pad, a heated mattress pad can have multiple heat settings and an auto-off feature which turns the mattress pad off after a set number of hours. This type of mattress topper can also be machine washed. A heated mattress pad can come in any size, and queen size and up mattress pads have separate controls for each side of the bed. Another mattress pad offering additional function is the waterproof mattress pad. It is a kind of mattress protector which has a vinyl barrier to prevent liquids from penetrating or staining, creating a waterproof mattress. It has all the features and comfort of a traditional mattress pad as well. A waterproof mattress protector can also protect against dust mites, mildew, and odors. This ‘all in one’ mattress protector has an antimicrobial agent which protects the fiberfill from these issues and increases the uses of the waterproof mattress pad. A waterproof mattress protector can also contain hypoallergenic polyester to give the mattress pad protection from allergens.