Climate and skin condition
Climate can make a considerable difference to the state of all our
skins. Where we live in the world, and whether we are adapted to the
local climate there, may also be critical.
The humidity of the air is important to the
way we feel and how our skin condition fares. Humidity is largely
determined by temperature: this is because the air can hold more water
vapour at higher temperatures. In winter the air cannot hold as much
water, and on a very cold day there is virtually no moisture in the
air at all. This is why we can often see people's breath in frosty
weather: as the warm, moist air from the lungs cools down, the water
vapour in it turns into tiny liquid drops that form clouds.
In hot weather, most of us find dry air more
comfortable and pleasant than very humid air. The tropics are hot
and humid, while Scandinavia can be warm and dry. Many people find
hot, humid weather trying and difficult to tolerate: this is the kind
of weather in which, in certain countries, seems to accentuate a tendency
for riots to break out! The skin, however, prefers humidity to dryness.
Skin condition
in winter
The condition of skin can change from day to day, and even from hour
to hour. It may be affected by general health, by changes in hormones
during the menstrual cycle and by the immediate environment. Skin
that felt normal in the morning may feel greasy and uncomfortable
after a day spent travelling in crowded trains and working in an office
with rather inefficient ventilation. |
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Skin needs to maintain water balance with
the environment for ideal function. As we have seen, the epidermis,
particularly the stratum corneum, acts as a partial water barrier,
helping to regulate the amount of water in the skin. This barrier
itself needs adequate water (more than 10%) to function properly.
Cleaning the skin after a day's work reveals how much sebum and
dirt was trapped in it. Much of this has to do with the amount
of moisture in the environment and the level of pollution.
This water is used to ensure that the other
vital part of the barrier, the lipid structures between the cells
of the stratum corneum, is maintained in a fluid state. Damage to
the stratum corneum - for example, by washing with harsh soaps,
which removes both external and internal lipids - can disrupt this
barrier and set up a 'vicious circle' of drying:
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