Plummeting temperatures and freezing conditions caused more misery for motorists today as forecasters warned of further snow to come.
Hundreds of drivers battled to get home after spending a night stranded in their cars in bitterly cold conditions as Scotland bore the brunt of a fresh wave of Arctic weather.
One retired couple was left "starving and freezing" for 17 hours on a journey which would usually have taken 40 minutes.
The most recent deluge - which appeared to take the authorities by surprise - forced people to sleep in their cars or abandon them as major routes became impassable.
Meanwhile 40% of children were turned away from class north of the border.
This came after around 100 youngsters were forced to sleep at their school because bad weather prevented them from getting home.
North-east Scotland and north-west England were battered by more snow and blizzards during the day as temperatures struggled to rise above zero.
While the mercury dipped to minus 18C in Strathallan, Scotland, last night, even at midday the highest temperature was only 4C, recorded in Penzance, Cornwall.
Forecasters said there was unlikely to be a let-up in the freezing conditions.
John Hammond, of the Met Office, said low temperatures and patches of freezing fog are likely to present the most serious problems.
"We've got a lot of cold weather to come in the next day or so," he said.
"It's going to stay largely dry in most places but temperatures will get down to between minus 10C and minus 15C.
"There'll be some snow showers brushing the coast and we could see several centimetres in some places later on tonight."
Up to 15cm was forecast for parts of Aberdeenshire, the Scottish Highlands and the North York Moors while Humberside, Lincolnshire and East Anglia may also wake up to a fresh covering.
Many places are expected to have their first frost-free night for more than a fortnight on Thursday, but next week is likely to herald more wintry weather, he said.
At least nine people have died so far in the big freeze, with an elderly man found dead in snow at a Lincolnshire caravan park becoming the latest victim.
Today police struggled to get Scotland's busiest roads open due to the number of cars abandoned overnight.
Pensioners Stewart and Kathleen Hendrie said they were trying to make their way home to Falkirk yesterday when they were caught up in the gridlock.
The couple left their daughter's home on Glasgow's south side at 10am yesterday and finally sought warmth in a hotel in Cumbernauld at 4am today.
Mrs Hendrie, 65, said: "The hunger we could deal with, but the worst thing was the intense cold. I didn't know how long we'd be stuck and at one point I joked with my husband that I thought I was going to get hypothermia."
She and her husband, 65, started to run out of fuel after leaving the engine running to keep warm.
"It was an appalling experience I would never want to repeat again," Mrs Hendrie added.
"We were starving, freezing and, above all, worried. If there's even one flake of snow that falls again I won't be going out in it."
Chief Inspector Stewart Carle, of Strathclyde Police, today advised stranded drivers to stay in their cars rather than venture out overnight.
His warning came as Scotland's Transport Minister Stewart Stevenson said the country was in the grip of the "worst snow and ice conditions since the 1960s", blaming inaccurate weather forecasts for the problems.
His Conservative counterpart Jackson Carlaw said: "There is no point in pretending other than that there has been a total collapse of our transport infrastructure."
Meanwhile, Transport Secretary Philip Hammond agreed to extend drivers' hours and working time rules for HGV drivers in Scotland for a further four days.
"I hope that this extension will assist in ensuring the delivery of vital supplies to the worst affected areas," he said.
The major airports were open today but officials warned of delays and cancellations due to fog and freezing weather.
The AA said it had attended a full day's worth of breakdowns by mid-afternoon, with calls peaking at around 2,500 every hour this morning - around two and a half times the normal rate.
By 3pm it had responded to 13,500 callouts and it expects to attend up to 22,000 by the end of the day - more than double the 9,500 on a normal Tuesday.
Since the first widespread snow on November 24, it has dealt with more than 230,000 - a 93% increase on the same period last year.
Meanwhile the RAC said breakdowns were 50% higher than normal.
Alan Wilcock, RAC Patrol Ambassador of the Year, said: "We're expecting another very busy rush-hour and evening as temperatures plummet again. The outlook for tomorrow morning is equally bad - with the cold set to play havoc with cars and roads yet again."