According to Chinese medicine, cold water, especially ice water, are a shock to the system, and also take a lot of energy to warm up to body temperature, and that effort drains us. At the same time, drinking water (perhaps with a little fruit juice) is excellent so that we stay well hydrated. There is evidence that it is best to drink it slowly - in small 2oz sips. Better to drink cold water than none, and better yet to drink cool, body temperature, or hot water or naturally decaffeinated or herbal tea. I used to find ice water essential. Then I learned it was becuase my body was out of balance. Now, balancing my health, I enjoy cool water, not cold.