- When people get wet in the rain, he freezes faster than if it remained dry.
- In the heat of the person begins to sweat.
- Hands in wet mittens freeze faster than in dry.
- When a person has a fever, doctors recommend wiping it with a wet sponge. And man is not so hot.
- Pouring water in the heat helps to cool down, even if the water is warm.
- When we come out of the water after swimming, we feel cold.
All these phenomena have the same explanation: water, getting to the skin, cooling it. Why? Because the water begins to evaporate, i.e. to change from liquid to gaseous vapour. And evaporation is a process that requires energy. Water takes this energy from the surface of human skin - evaporation due to the heat produced by our body. And if the body take the heat, it cools.
And did you notice that the wind freeze faster than in calm weather? This is because the water evaporates, forms around the body of the layer of air saturated with vapor. Because of this evaporation is reduced. When the wind blows, it blows this layer, the air around you becomes drier, and evaporation increases.
Thus, how quickly cools the body, depends on the ambient humidity. In the water body is cooled faster than in cold air. The more humid the air, the more cooling it acts on the body. But in the heat if the air is humid, the water evaporates bad. So humid and hot climate, we move hard (for this phenomenon, we use the term "FuG"): we're sweating, but ease it brings. The more the air of moisture in the heat, the hotter and desnee weather on our feelings. In dry air the body intensively sweats, the sweat evaporates from the skin surface and the body loses a lot of heat. Due to this, maintains normal body temperature.