Wind chill is the meteorological index that combines the effects of wind speed and temperature.
If you've ever stood outside on a cold windy day, you know that the wind can make you feel much colder than the air temperature might indicate. The reason is that the wind blows away the thin layer of warm air that normally surrounds your your body. Clothing acts as insulation to help trap this warm air, which is heated by your skin. The stronger the wind and the lower the temperature, the more rapidly you lose body heat. The technique for measuring wind chill was developed by scientists in Antarctica during the Second World War.