This will not help to restore moisture, however. It may even encourage more water loss, since the air in centrally heated houses is often drier than that outside!

Sebum production in winter
Sebum (the lipid mixture produced by the skin's sebaceous glands, see page 34) is produced at a fairly constant rate in each individual, though rates vary from one person to another and tend to be higher overall in the teenage years. It does not change in response to time of day or season, though sebum will obviously build up on the skin throughout the day. (This is why skin feels sticky at the end of the day.)
    Since sebum production is neither significantly lower or higher in the winter, there is no need to use a moisturizer with extra (or less) 'oil' in the winter to compensate for a lack (or excess) of sebum.

Skin appearance in winter

As we have seen (page 10), the skin's response to cold is to close down the small blood vessels in the dermis. This diverts blood from the surface of the body to the inside, and helps to check heat loss.
    The result can be that in cold weather skin loses the glow it normally gains from blood flow close to the surface, and it can tend to look dull and lifeless. Massaging with a moisturizer will help to stimulate circulation near the surface

and give the skin more color, as well as improving the water content. You can do this as often as you need to - you can't over-moisturise!
    Some people have a particular sensitivity to even slight drops in the air temperature, resulting in the ends of their fingers going white. This is called Raynaud's phenomenon: although it can be painful it is otherwise harmless.

The essentials of winter skin care Use a good moisturising product during the day - it doesn't need to be a heavy cream, but it does need to hydrate well. Use it liberally and often. At night, use a good night cream. Night creams are specially formulated with a higher lipid content than would normally be comfortable in the day, to help restore softness to the skin. Do not wash with harsh soaps. Soaps dry the skin and exaggerate the effects of the cold. Use a good-quality mild cleanser formulated for 'sensitive' skin. Stay warm! Keep well wrapped up, to help maintain a soft skin by preventing excessive TEWL.