人們都知道，在溫度相同的情況下，有風(fēng)的冷天會比無風(fēng)的天氣感到寒冷。那是因為人體產(chǎn)生的熱量會溫暖體外薄薄的一層空氣，對我們的體溫有保護作用。而有風(fēng)的天氣這層暖空氣會被吹散，加速體溫的流失。在加拿大，每年都有近80人因寒冷而死。

    Anyone who's been outside on a windy, winter day knows it's a lot more difficult to stay warm than on a calm day with the same temperature.

    On a calm winter day, our bodies warm up a thin layer of air close to our skin -- called the boundary layer -- and that helps to insulate us from the cold air. However, when the wind starts to blow, it strips away this boundary layer and our skin is more exposed to the cold air.

    Because wind chill speeds up the rate at which your body loses heat, it can be dangerous. Each year in Canada, more than 80 people die from overexposure to the cold.