In terms of choosing skin care products in winter, make sure they contain humectants that absorb moisture and send it to the epidermis, a sealant such as petroleum jelly can trap in moisture, and emollients like lanolin can soothe the skin.

You may have found a moisturizer that works well in spring and summer. But as the weather changes, you may find you cannot stop the dryness no matter how thickly you apply the moisturizer. Find an ointment moisturizer that is oil-based, rather than water-based, as the oil will create a protective layer on the skin that retains more moisture than a cream or lotion.

Some of the most effective and least expensive moisturizers are petroleum jelly and mineral oil, which prevent water loss without clogging pores. Because they contain no water, they are best used while the skin is still damp from bathing, to seal in the moisture.

Externally, while the outdoor environment is bad for skin, indoors is also hostile. Central heating systems and air-conditioning blast hot, dry air throughout rooms and offices, which makes humidifiers necessity. Putting wet towels or a soaked sponge on your desk also helps.

If the indoor humidity is adjustable, set it to around 60 percent, a level that should be sufficient to replenish the top layer of the epidermis.

Air pollution tends to be more severe on cold days, but that does not make the skin dirtier. Do not wash your face too much. It is a good habit to wear a mask to avoid exposing the skin to the winter wind.

Good sleep is essential. Traditional Chinese medicine theory holds that staying up late will injure the Yin essence, causing the loss of body fluids, thus depriving the skin of moisture and dulling its glow.

Contact the writer at wuni@chinadaily.com.cn.