1) It can be hot for pain relief 2) Liquid container 
==Types of water bottles== ===Single-use plastic water bottles=== Water bottles sales have increased almost every year in the United States for more than a decade. In 2011 over $11 billion was spent on bottled water products in the US. The International Bottled Water Association (IBWA) states that Americans are increasingly relying on them due to ...
[n] - a bottle for holding water
noun a bottle for holding water