AS the weather warms, it's tempting to start peeling off clothes, taking off hats, leggings and wearing shorter skirts and short-sleeved shirts. But experts warn against stripping down too soon in spring.

Traditional Chinese medicine doctors say the average daily temperature should be above 15 degrees Centigrade before people start taking off the wraps and wearing lighter-weight clothes. This is especially true for those who are weak or elderly.

A Chinese proverb goes "chun wu qiu dong," or bundle up in spring and stay cool in autumn (literally spring muffling, autumn freezing), so keep warm for a while.

That's not a tall order these days as Shanghai weather has been changeable and chilly.

According to TCM, spring is the season for new growth when yang ("hot" energy) rises in the universe and gradually builds. But in early days the yang is still to weak to resist the still-cold environment, just as vegetable sprouts need a greenhouse in early spring.

Wu (bundling up) is necessary for people as well so the yang energy can gradually each its peak in summer.

Low-level yang in early spring can mean lower immunity and the body can be vulnerable to "invasion of pathogenic energies" that cause illness.

In the Tang Dynasty (AD 907-960) people were warned against wearing light clothing in spring, lest they catch typhus or cholera and suffer indigestion and headaches. That was the advice from Sun Simiao, the "medicine king" in his famed "Qian Jin Fang" ("A Thousand Golden Prescriptions").

Today TCM practitioners say the reasons for keeping warm are frequent temperature changes and the significant difference between day and night.

In Shanghai, the temperature has been as high as 20 degrees Celsius and as low as zero in the past couple of weeks and the recent daily range is around 8 degrees. There's a big difference between indoor and outdoor temperatures.

"The body's temperature adjustment system is still in the winter mode, so heavy clothes help keep in the heat," says Dr Zheng Minyu, head of the Internal Medicine Department of Longhua Hospital attached to Shanghai University of TCM.

"The body cannot effectively protect itself when facing sudden temperature changes," Dr Zheng adds.

This means immunity may be lower in spring and since many viruses become more active, lightly dressed people may be more vulnerable to respiratory and other infections.

Keeping the legs and feet warm is top priority in springtime muffling. Many people tend to change heavy trousers for lighter ones, but as blood circulation is poorer in the lower half of the body, the legs and feet need more protection than the trunk and arms, especially for the elderly and for children. Otherwise, joint problems and vascular problems may recur.

As for other clothes, Dr Zheng suggests taking off heavy clothes at midday when it's sunny and comfortable and putting them back on when the temperature drops.

Patients with chronic asthma, bronchitis, arthritis, and cardiovascular ailments should keep specific parts of their body warm, says Dr Zheng.

For example, those with respiratory problems should always wear scarves to protect their neck; people with joints problems should keep their knees warm with heavy trousers or knee pads; people with cardiovascular problems should protect their head to avoid sudden stroke.

Use common sense.

If the average daily temperature for three days is above 15 degrees, it's generally safe to take off heavy jackets and pants. If you take your clothes off too soon, you may be afflicted by shang huo (fire ascending). Bundle up if it gets cold.

MA lan (kalimeris indica, sometimes called Indian aster) is a popular wild vegetable that comes onto the market in spring. It's rich in vitamins, minerals and microelements, including vitamin A, carotene, potassium, calcium and phosphorous.

Traditional Chinese medicine classifies ma lan as a mildly "cold" food that helps dispel pathogenic heat, stop bleeding, promote urination and relieve inflammation and edema. It is especially recommended as dietary therapy for those with sore throat, tonsillitis, bleeding problems, liver inflammation, and tonsillitis.

To relieve acute sore throat, tooth ache

Cook soup with 60-120g fresh ma lan, or 30-60g dried ma lan.

Drink twice a day.

To relieve high blood pressure and eye pain

Cook soup with 30g ma lan roots and 25g dried sheng di (rhizome of rehmannia).

Eat a portion at morning and one at night. Eat frequently.

Ma lan, peanuts and tofu

Ingredients: Fresh ma lan (250g), fried peanuts (50g), 5 pieces of tofu

Preparation:

1. Grind peanuts, chop tofu into small pieces.

2. Quickly boil ma lan with water and pluck it out.

3. Chop ma lan into fine tiny pieces and mix it with the peanuts and tofu.

5. Dress it with soy sauce, sesame oil, salt, and sugar.

Benefits: Helps dispel pathogenic heat, promote urination and relieve edema.

Ma lan congee

Ingredients: rice (50g), ma lan (15g)

Preparation:

1. Chop ma lan into small pieces.

2. Make congee.

3. Add ma lan when it's almost done.

4. Season

Benefits: Helps dispel pathogenic heat, relieve bleeding, benefit the spleen and improve appetite.

Ma lan and lotus seeds soup

Ingredients: ma lan (15g), lotus seeds (15g), dried jujube (15g)

Preparation:

1. Cook ma lan in a saucepan with water for an hour.

2. Filter the soup, add lotus seeds, jujubes and a little more water.

3. Cook for two hour at low heat.

4. Add sugar to sweeten.

Benefits: Helps dispel pathogenic heat, relieve bleeding and benefit the spleen.

What to keep warm

Digestive problems

Keeping the stomach warm and keeping the tummy covered is essential for those with digestive problems such as diarrhea, swelling and upset stomach.

Keeping ankles warm and wearing thick socks also protects the digestive system because san yin jiao, the acupuncture point on the inside ankle, is linked to the digestive system.

Chronic bronchitis, lung inflammation

It's essential to wear a scarf to protect the neck and ward off pathogenic cold in the respiratory system. Keeping the calves warm can help prevent and relieve problems.

Feng long, the acupuncture point on the outer calf, helps relieve coughing, dissolve phlegm, relieve dizziness and numbness.

Wearing heavy trousers or thick leggings helps.

Prostate problems

Patients with prostate problems should keep their calves warm. That's because yin ling quan, the acupuncture point at the back of the calf, reinforces energy, activates energy circulation and benefits the kidneys (term for the reproductive system).

Keeping the calves warm and massaging the acupuncture point can help relieve edema, difficult urination and involuntary urination.

High blood pressure

Apart from keeping the head warm (this helps prevent stroke, it is said), the instep should be kept warm.

Tai chong, the acupuncture point between the first and second toes, helps relieve headache and high blood pressure.

Wearing thick socks is advised.