Chinese medicine refers to our metabolism as our ¨digestive fire¨. If we drink ice water, the body then has to work to heat it up to our body´s temperature before it can be absorbed for use, slowing down its ability to do its primary job of breaking down food. Therefore, drinking room temperature or warm water, helps keep our digestive fires strong.
A person´s constitution as well as seasonality can also come into play. Although TCM will always recommend room temperature or warm over cold water, it would make more of a difference for a person who has a tendency towards running cold, a weak digestive system and during the winter months, than for a person who has robust digestion, always runs hot and is battling the warm sun of mid-summer.
Before studying Chinese Medicine I didn't really pay much attention to the temperature of the water I was drinking. Here in the United States, we operate under the assumption that water should be served chilled or with lots of ice.
On a personal note, and speaking as someone who often runs cold and lives in the typically cool and damp climate of San Francisco, it now strikes me as odd to walk into a restaurant on a cold and rainy day and still have an ice cold glass of water plunked down in front of me. The point of this post is not to suggest that ice water is wrong, but to offer up an alternative perspective as food for thought and invite you to explore if changing the temperature of the water you drink can improve the way you feel.