Safe, nontoxic construction: The thermos is made of PVC and is nontoxic. It features a nonslip, antiscald mesh textured surface for secure handling and effective heat transfer. The furry lid is soft against the skin and provides a comfortable barrier from heat. Comfort and warmth design: The thermos bottle bag helps you stay cool in hot summer and warm in cold winter. It includes a soft cover to prevent burns from direct skin contact while helping retain warmth. Filling and lid care: The thermos can only be filled up to 2/3 of its water capacity. The lid is washable. Simply fill with hot water into a small thermos and tighten the stopper. Warning: for safety reasons, never use boiling water. Practical uses: Wearable hot water bottle for warmth, relief from muscle soreness, and to ease a stiff neck or back pain. Can be used as a cold compress to fever or subsidence of minor swelling wounds. Ideal for snuggling in bed, staying warm on cold winter nights, and as a heat pack to soothe menstrual cramps and sore muscles. Use scenarios: Warmth and muscle relief: Wear it to alleviate muscle soreness, neck or back stiffness, and to stay cozy during cold nights. Cold or swelling care: Use as a cold compress to address fever symptoms or minor swelling. Comfortable heat therapy: Use in bed or while resting to soothe menstrual cramps and general muscle discomfort.