A reusable water bottle is a great way to ditch disposable plastic bottles and help the environment. But did you know it's imperative to rinse the bottle every day? Just like a coffee mug, utensils or a plate, a reusable bottle (and the lid) should be rinsed with hot, soapy water. If you don't wash it, you risk having harmful bacteria grow inside, which can make you sick. If you are using a reusable bottle at the office and don't have time to rinse it, try this one trick: Leave it in the fridge. A refrigerated bottle won't have the warmth to grow germs and bacteria overnight.