This winter could be the coldest in Scotland since records began.
With temperatures plunging, bookmakers have cut the odds on a record-breaking cold snap.
Lows of -12C are predicted within the next few weeks, with snow also on the cards.
Scotland will be colder than the Arctic Circle, leading transport providers and local authorities to gear up for a big freeze.
It comes as a fresh Met Office yellow warning of ice and snow has been put in place for Tayside and Grampian from 6pm on Wednesday until 11am on Thursday.
This morning the A93 Braemar to Perth road was closed at the Spittal of Glenshee due to wintry showers.
A spokesman for Ladbrokes said: “It’s ‘snow’ surprise punters are backing this winter to be the coldest on record.”
The firm has slashed the odds on winter being the coldest ever – beating 1962-63’s UK average temperature of -0.18C – to 5-2.
The coldest December on record was in December 2010 when Tayside and Fife was brought to its knees by “thunder snow”, with the freezing conditions persisting from late November into January.
Meanwhile, Network Rail has revealed it will use a thermal-imaging helicopter and 34 de-icing trains to keep tracks clear. Empty “ghost trains” will also run at night in a bid to clear snow and ice ahead of peak commuting times.
A Network Rail spokesman said: “Our thermal-imaging helicopter carries out aerial inspections to guide engineers to points heaters that aren’t working effectively.”
A total of around 5,000 gritters are on standby across Scotland.
Transport Minister Humza Yousaf said: “Our winter service capability has never been higher.
“There is no room for complacency despite the recent mild winters.”
A Transport Scotland spokesperson added: “We plan across the year for our winter service.”
Local authorities have resilience plans in place for winter, with a spokesman for the Convention of Scottish Local Authorities saying: “Scotland’s councils take their duty very seriously.”
Edinburgh Airport has 20 snow and ice-clearing vehicles and 80 staff on standby.
An airport spokesman said: “We’ll be working round the clock to make sure weather has the least impact possible on our passengers.”
Glasgow Airport is understood to have 18 snow-clearing vehicles available.
The Met Office said temperatures could hit lows of -7C tonight and -10C tomorrow night.
While daytime totals should rise above 0C, Arctic windchill will leave it feeling much colder.