Airports have been forced to cancel dozens of flights as ice and thick fog descended on the UK overnight. Daybreak's Jonathan Swain reports from Heathrow Airport:
Clear skies and light winds are a recipe for fog to develop, so allow extra time to defrost your car and check before you travel.
It's another bitterly cold day today. It's all down to where the air originates from - and today's can be traced back to Russia.