What is the "Wind Chill" effect?
Among the many difficulties you can meet in the mountains, the wind is one of those factors that can take on completely different characters depending on the season.
In summer, when you go to the mountains looking for cool air, the wind can be a pleasant relief, making walking much more agreeable. In winter, on the other hand, cold wind can be a real problem, making movements difficult, upsetting the hiker's balance and above all stealing precious heat from the body.
Let's see how to deal with the wind in the mountains.
The first thing we must do is learn to know and understand the reasons why winds form, as explained in the chapter devoted to it in the meteorology section. Knowing the wind can give us useful information about its temperature, its direction and its likely duration over the course of the day.
Depending on the speed of the wind, the temperature perceived by the body changes. To know the temperature perceived by the body under the effect of the wind, reference is normally made to the calculation of the so-called “wind chill”. It is a table in which wind speed and the temperature perceived by the body are related to each other.
But what exactly does perceived temperature mean?
The wind, with its constant action of renewing the air around the body, continually strips away very thin layers of warm air in contact with the skin. The continuous action of the wind on the body lowers its temperature enormously, much faster than would happen if the air were still.
A first step to counter the Wind Chill is to cover your body with many different layers of clothing. Between the layers, pockets of lukewarm air form that insulate you from direct contact with the cold and from the action of the wind. In reality it is a matter of keeping part of the heat inside your clothing.
To protect yourself from the cold wind you first need to protect your head with a hat. The head, in fact, being the part of the body best supplied with blood, can lose a great deal of heat.
On days with clear skies, strong sun and strong wind, to avoid having to wear too warm a hat it will be enough to protect the ears, which are more sensitive to the “wind chill” effect, with an ear band.
The abdominal area must also be protected from the wind, as it too is richly supplied with blood vessels, and so must the inner thigh, through which run the two great arteries that supply the legs. In this case a pair of shorts in synthetic fabric, of the running type, worn under your normal winter hiking trousers, will be enough. Shorts of this kind can cover the lower part of the abdomen and the thighs without covering the rest of the legs too much.
The hiker should pay particular attention to the action of the wind, especially when the clothes in contact with the skin are damp. In this case the Wind Chill effect is made even worse, because the moisture in contact with the skin speeds up the loss of heat as it evaporates outwards.