![]() When humidity is high, this evaporation reduces resulting in 'feels like' temperatures that appear warmer than the actual air temperature. When a human perspires, the water in the sweat evaporates leading to the cooling of the body as the heat is carried away. For example, with an air temperature of minus 20. When the wind speed is low in periods of high temperatures, the 'feels like' temperatures become more impacted by the humidity level. The blue-shaded areas in the wind chill chart represent the amount of time it takes to get frostbite at the corresponding wind chill temperatures. If it is windy, the wind will take the boundary layer away and the skin temperature will drop making us feel colder. ![]() On a calm day, our bodies insulate us with a boundary layer which warms the air closest to the skin. When its 0 degrees and the wind is 15mph (considered 'breezy' by the National Weather Service), youre at risk of frostbite in a little over half an hour. An example of this is in winter when winds blowing to the UK from a north- easterly direction make the 'feels like' temperatures colder than the actual air temperature. For example, a temperature of 0☏ and a wind speed of 15 mph will produce a wind chill. 'Feels like' temperatures throughout the year are particularly influenced by wind. Each shaded area in the chart above shows how long a person can be exposed before frostbite develops. This has the effect of moving heat away from the body and making the surrounding air feel colder than it actually is. The 'feels like' temperature is especially important on windy days due to the effect of wind on the evaporation speed of moisture from skin, the stronger the wind, the faster the cooling of the skin.
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