A hot-water bag is an item that is used to alleviate discomfort by applying heat to an aching area. Although it's an essential tool, it's important to know that there are other synonyms that we can use instead of just calling it a hot-water bag. Some common synonyms are a heating pad, a heat wrap, a warmth sack, a heat therapy bag, and a microwavable heat pack. All of these describe the same thing- an item that is designed to deliver heat therapy for your aches and pains. Knowing these synonyms comes in handy for those times when we need to communicate effectively to our friends or healthcare professionals.