WITH the end of the plum rains, Shanghai is entering the hot dog days and it's time to enhance your yin or internal cold energy. That doesn't mean a lot of cold food and frosty drinks - too much can upset the digestive system.

Traditional Chinese medicine recommends "cold" energy foods such as pearl barley, white gourd, white turnips, lettuce, green beans, watermelon, cucumber, seaweed, lotus root, sugar cane, bananas, apples, mandarin oranges, bamboo shoots, tea (hot tea is cooling), yogurt, and many other foods.

Summer in Shanghai is hot and damp and our bodies also heat up. When there's too much internal heat and damp, they become pathogenic energies that can cause illness.The stomach and spleen (the digestive system) become especially vulnerable. Too much icy foods, ice cream and cold drinks can cause diarrhea and indigestion. People with ulcers, gastritis and stomach conditions should be careful.

Respiratory patients also should avoid too much cold food and drink that can aggravate their condition - cold causes blood vessels in the throat to constrict. A weak throat is vulnerable to invasion by pathogenic energies.Some people lose their appetite in hot weather. Iced drinks won't bring it back - they contain too much sugar and cream.

Icy foods and drink after a meal are not healthful. After we eat, blood flows to the digestive system, but cold food and drink will make the blood vessels contract. That lessens the amount of blood for digestion.Ice cream and cold drinks also speed up the gastrointestinal tract, so organs cannot properly absorb nutrition.

Think of other desserts, cakes, custards, fruits.TCM recommends hot or warm drinks, even in summer, for people with digestive problems as they can help balance energy in the stomach. The ideal is tea around 30-32 degrees Celsius, close to body temperature. Even healthy people should not overindulge in icy food and drink, especially on an empty stomach.