棉被 (mián bèi) is a traditional Chinese quilt filled with processed cotton, widely used for warmth during cold weather. The first character 棉 (mián) means 'cotton' — referring to the soft, fluffy plant fiber used as insulation — while 被 (bèi) means 'quilt' or 'blanket', a general term for bedding that covers the body during sleep. Together, they specify a quilt whose filling is natural cotton, distinguishing it from modern alternatives like polyester-filled or down quilts.

棉被 is especially common in northern and rural China, where winters are harsh and homes may lack central heating. It’s valued for breathability, durability, and gentle warmth. Many families hand-make or refurbish cotton quilts seasonally, and some still air them in sunlight to refresh and disinfect — a practice known as 'sunning the quilt' (晒被子). Though less common in urban apartments today, 棉被 remains culturally resonant and appears frequently in literature, family stories, and seasonal routines.