Dried items are usually soaked in water to rehydrate before cooking. Therefore, it is necessary to adequately rehydrate to replace lost fluids. Before being eaten, they are usually boiled in water or soup to rehydrate them. If it encounters moisture, "Selaginella lepidophylla" may rehydrate and take root in the new location. This ration is shelf stable and may require water to rehydrate some of the contents. David Nalin discovers that oral therapy can work to rehydrate cholera patients. As a result, he has to be submerged in the Sanzu River to rehydrate.