Bedding, also known as bedclothes or bed linen, is the materials laid above the mattress of a bed for hygiene, warmth, protection of the mattress, and decorative effect. Bedding is the removable and washable portion of a human sleeping environment. Multiple sets of bedding for each bed will often be washed in rotation and/or changed seasonally to improve sleep comfort at varying room temperatures. In American English, the word bedding generally does not include the mattress, bed frame, or bed base (such as box-spring), while in British English it does. In Australian and New Zealand English, bedding is often called manchester. A set of bedding usually consists of a flat or fitted bed sheet that covers the mattress; a flat top sheet; either a blanket, quilt, or duvet, sometimes with a duvet cover which can replace or be used in addition to the top sheet; and a number of pillows with pillowcases, also referred to as pillow shams. (See #Terminology for more info on all these terms.) Additional blankets, etc. may be added to ensure the necessary insulation in cold sleeping areas. A common practice for children and some adults is to decorate a bed with plush stuffed animals, dolls, and other soft toys. These are not included under the designation of bedding, although they may provide additional warmth to the sleeper.