The microclimate consists of a combination of temperature, moisture level and ventilation on and around the skin. A healthy microclimate is comfortable to the skin and protects it against damage and injuries. The skin’s microclimate is, besides pressure and shear forces, an important factor for the development and prevention of bedsores.
The skin’s task is to protect the body and regulate the body temperature, which is 37,1 degrees Celsius on average. Sweating is very important for regulating the body temperature. After the sweat is excreted out of the body, it evaporates. The evaporation process uses heat from the body, so the body and skin are cooled. An important condition for evaporation is the air humidity: the surrounding air must be dry enough. If the air humidity is too high, the air can absorb little or no extra moisture, which stops the evaporation of sweat and consequently the cooling of the skin. This makes the skin feel wet and clammy instead of comfortable.
Temperature and moisture each affect the health of the skin in their own ways.
A higher temperature of body tissue results in increased “metabolic activity”, meaning that the cells are more active and need more oxygen and nutrients. If at the same time the skin is pinched by pressure and/or friction, the circulation through the blood vessels will stop. This can cause a shortage of oxygen and nutrients and the tissue might get damaged. This effect worsens because the skins is weaker at higher temperatures. If the skin temperature is around 35 degrees Celsius the upper layer of the skin (the so-called ‘stratum corneum’) is only a quarter as strong as it would be at a lower temperature of 30 degrees Celsius.
Moisture is also of big influence on the health of the skin. The skin becomes stiffer when the moisture level is higher; the so-called ‘coefficient of friction’ increases. This makes the skin more sensitive to pressure and friction. High humidity of the skin softens the connections in the collagen between the cells. Collagen keeps the skin resistant and flexible so if the collagen becomes soft, the skin gets damaged more easily
The regulation of the microclimate is important for both the comfort and the protection of the skin. Moistures should be absorbed immediately, so the skin remains strong. Sufficient ventilation keeps the air humidity at an acceptable level. This allows evaporation to take place and cools the environment around the skin and body.
When choosing textile that will be in direct contact with the skin, it is important to make sure the textile does not get too moist itself. A common misconception is that the use of certain ‘natural materials’ is a good idea. These ‘natural materials’ often consist of substances that absorb the moisture, instead of spreading and evaporating it. That only works temporarily. As soon as the textile is saturated, it will stay wet and clammy. This makes the air humidity even higher, and that is the exact opposite of what we try to achieve.
