Thousands of people stay on the frozen Aussenalster river during the “Alstervergnuegen” on February 10, 2012 in Hamburg, Germany. The very popular annual city festival “Alstervergnuegen” takes place around the Alster lake in Hamburg. Last time the Alster was official approved for the 'Alstervergnuegen' is 15 years ago. (Photo by Joern Pollex/Getty Images)

A man walks up a snow covered hill on Wimbledon common on February 10, 2012 in London, England. The Met Office cold weather alert remains at Level 3 as southern parts of England continue to suffer from cold weather and freezing conditions, with further snowfall overnight. (Photo by Peter Macdiarmid/Getty Images)