Salt therapy pillows are made entirely of natural Himalayan salt crystals. Salt retains temperature exceptionally well, whether hot or cold. The pillow’s weight provides gentle pressure while comfortably conforming to the natural curves of the face and body. These Large Back and Stomach Therapy Pillows are simple to heat and provide a soothing hot therapy treatment with warm, moist heat that penetrates your skin and works your muscles and joints. Furthermore, these Body Relief Pillows are ideal for relieving pain in the neck, shoulders, knees, spine, and other areas.