Bamboo is a natural fiber like cotton and linen. Unless your pajama is heavily soiled, use cold water and the gentle wash cycle for regular care. For heavy soil, use warm water in your washer and allow clothing to presoak to remove excess soil. Never use hot water for regular washing when cleaning bamboo, because it can cause the fabric to shrink. It is best to let the pajama air dry. If quicker drying is needed, use the low heat cycle of the dryer.