If we drink or eat chilled, cold, or frozen foods or drink iced liquids with our meals, we are only impeding the warm transformation of digestion. Cold obviously negates heat, and water puts out fire. This does not mean that such foods and liquids are never digested, but it does mean that often they are not digested well. In Chinese medicine, if the stomach/spleen fail to adequately transport and transform foods and liquids, a sludge tends to accumulate just as it might in an incompletely combustion automobile engine. This sludge is called stagnant food and dampness in Chinese medicine.