In Chinese medicine, there is an important distinction made between the cold physical temperature of a food or drink their post-digestive temperature. Post-digestive temperature refers to a particular food or drink’s net effect on the body’s thermostat. Some foods, even when cooked, are physiologically cold and tend to lower the body’s temperature either systemically or in a certain organ. In Chinese medicine, every food is categorized as either cold, cool, neutral, warm or hot. Most foods are cool, neutral or warm and in general, we should mostly eat neutral and warm foods since our body itself is warm. During the winter or in colder climates, it is important to eat warmer foods, but during the summer we can and should eat cooler foods. However, this mostly refers to the post-digestive temperature of a food.
If one eats ice cream in the summer, the body at first is cooled by the ingestion of such a frozen food. However, its response is to increase the heat of digestion in order to deal with this cold insult. Inversely, it is a common custom in tropical countries to eat hot foods since the body is provoked then to sweat as an attempt to cool itself down. In China, mung bean soup and tofu are eaten in the summer because both these food tend to cool a person down post-digestively. If we are going to eat cold and frozen foods and drink iced, chilled liquids, it is best that these be taken between meals when they will not impede and retard the digestion of other foods.
Many Westerners are shocked to think that cold and frozen foods are inherently unhealthy since they have become such an ubiquitous part of our contemporary diet. However, chilled, cold and frozen foods and liquids are a relatively recent phenomenon. They are dependent upon refrigeration in the marketplace, during transportation and in the home. Such mass access to refrigeration is largely a post World War II occurrence. That means, in temperate zones, people have only had widespread access to such cold temperature foods and drinks for less than 70 years. 70 years is not even a blink on the human evolutionary scale.