The 30 hottest days in summer, or san fu, are the time to take care of your health in winter. During san fu, (each fu 10 days, called chu fu, zhong fu and mo fu), traditional Chinese medicine hospitals are crowded.

It's part of the tradition of dong bing xia zhi, literally treating winter ailments in summertime.

The dog days usually run\ from mid-July to mid-August, and this year starts on July 14.

This is the time to nourish yang (hot) energy for winter, relieve and prevent chronic pathogenic cold-related ailments that plague us in winter. It is said that carrying out dong bin xia zhi for three consecutive summers will help rebalance energy and dramatically improve health in winter.

Treating winter ailments in summer is based on the TCM theory of the correspondence between human beings and the universe. Seasonal changes directly influence the energy balance within the human body.

The yang energy in the body increases and inhibits pathogenic cold, and yang energy peaks in summer's dog days.

"Cold-expelling" therapies applied now can help accumulate yang energy, thus helping to prevent relapses in the winter.

A lack of yang energy and invasion of pathogenic cold contributes to colds, sore throat and respiratory ailments, as well as arthritis, rheumatism, asthma, etc.

There are numerous ways to treat winter ailments in summertime. They include drinking herbal medicine soup, medicinal tea and medicinal wine, eating herbal foods, taking medicated baths, receiving treatments like fumigation, massage, moxibustion, acupuncture, huo guan (fire cupping), gua sha (scraping), hot compress and fu tie (application of herbal plasters).

Fu tie is very popular as it is considered especially effective in relieving and preventing relapse of chronic winter ailments like rheumatism and asthma.

It's best to receive this plaster treatment in the dog days for three years.

There are other effective treatments, including some that are easy to carry out at home. And any hot summer day is a good choice.

If you don't want acupuncture, moxibustion or a herbal pack applied by a TCM practitioner, you can apply hot compresses on your neck in summer to relieve and prevent cervical vertebrae problems.

According to TCM, aches are caused by energy stagnation; pathogenic cold and dampness accumulating in the neck block the energy and blood circulation there and lead to aching and stiffness. If stagnation is eliminated and pathogenic cold and damp dispelled, it is less likely for neck aches to recur.

Hot packs are good in summer because as the pores open in warm weather, warm energy is more easily absorbed into the energy channels to dispel pathogenic cold and damp, according to Lu Yiping, professor of the Shanghai University of TCM.

The water needn't be very hot, says Lu. Usually, 50 degrees centigrade is best. Lu suggests mixing boiling water and cold water in equal proportions in a hot water bottle. Wrap in a towel and apply for 20 minutes twice a day for several days.

You can also prevent winter aches and pains by reinforcing the kidneys and liver in summer because, according to TCM, "the kidneys govern the bones while the liver governs the tendons."

Thus, it's advised to eat white fungus, black fungus, papaya, walnut, sesame and mushroom.

Herbal external packs on the navel area in summer can help relieve pathogenic cold-related stomach problems in winter. Mix about 10 grams of ground evodia (zhu yu) fruit powder with vinegar. Stir until it has a gooey consistency, apply on the navel, cover with gauze and a rubberized watertight fabric. Change very 12 hours for one week. It helps dispel pathogenic cold and warms the stomach, thus relieving chronic stomach problems in winter.

Crucian carp soup with sha ren (cardamom) can also help treat cold-related stomachache.

Pig's lung soup with lily root and white fungus is recommended for those with chronic respiratory problems such as asthma.

Apart from taking treatments and eating right, people should guard against pathogenic cold. Those who have joint pains or numbness in the limbs should not sleep outside in summer. Those prone to headaches should never wash their hair with cold water, even in summer.

Those prone to winter ailments should not face air-conditioner or electric fans directly for long periods. They should avoid iced drinks, fruits and foods. Never take a cold shower after sweating - your yang energy will be severely damaged as pathogenic cold easily invade through your open pores, according to Lu.

(Shanghai Daily June 2, 2009)