Why do they use rubber for hot water bottles?

Well, isn't that a happy little question! They use rubber for hot water bottles because it's a flexible and durable material that can hold hot water safely. The rubber helps retain heat for a longer period of time, making it perfect for keeping you warm and cozy on a chilly night. Just like painting a beautiful landscape, using rubber for hot water bottles is a simple yet effective way to bring comfort and joy into our lives.