We take a look at where they come from and how best to use them . So , as winter officially comes to half the world , today we celebrate an expression that means winter is coming . When temperatures drop and a cold snap comes , that means one thing : Jack Frost has arrived ! Jack Frost represents the coming of dark , cold days . He is the personification of winter , a human form of winter weather . So , when we say , “Jack Frost is nipping at your nose ,” we mean that you feel the cold , icy effects of winter on your face . When a frost or deep freeze comes , you had better bundle up ! You should wear enough clothing to stay warm . Now , Jack Frost does , indeed , bring the cold of winter . But he can also create beauty in nature . Some traditions claim that Jack Frost is responsible for leaving ice and snow on windows , trees , the ground…anywhere it will stick . That is what poet Hannah Flagg Gould (1789-1865 ) must have been thinking when she wrote a poem called The Frost . Here are parts of that poem . THE FROST looked forth , one still , clear night , And he said , “Now I shall be out of sight ; ... Then he went to the mountain , and powdered its crest , He climbed up the trees , and their boughs he dressed With diamonds and pearls … With all of its beauty and extremes , winter is a great subject for songs and poetry . But now , let's listen to how we use these wintry expressions in conversation : It is freezing outside . This cold snap came out of nowhere ! I don't care how cold it is . I'm going on a hot date ! Is that all you're wearing ? You need to bundle up or Jack Frost will be nipping at more than your nose ! I'll be fine . I'm wearing my new coat . That it is NOT a winter coat . I mean , it looks great , but it's much too thin . You will catch a cold . You can wear my new down coat . It keeps you warm up to minus 30 degrees Celsius ! I'm going on a date...not exploring the Arctic Circle ! Besides , the taxi will take me from door-to-door . But what if something goes wrong ? What if the car skids on the ice and is involved in an accident ? You'll have to walk to the restaurant . You might freeze to death ! No , I won't . I'll just call an Uber to come and get me . And what if that vehicle runs out of fuel ? Then you'll have to walk to get more . No , the Uber driver will . I'll just call another car . What if that new Uber driver is a pregnant woman and she goes into labor ? You'll have to help . You'll have to wait outside in the cold until help arrives ! And the roads are already covered with five centimeters of snow ! It could take the ambulance an hour to get to you ! If you're wearing that thin coat…you'll catch your death !! The EMTs will find you frozen solid like a block of ice !! Give me your coat ! Here's my ride …