A tiny village in the Highlands has experienced the coldest night of the winter in the UK.
Across Scotland, temperatures overnight dropped well below freezing with -22.3C recorded at Altnaharra in Sutherland.
The remote village already shares the record for the lowest temperature ever recorded in the UK, having experienced -27.2C on 30 December, 1995.
The Met Office said temperatures were set to stay below zero and there was a risk of further snow in the north.
Two police officers were hurt when their stationary car was hit as it attended the scene of another crash.
The officers were at an accident involving four vehicles on the A90 outside Forfar, Angus, when the second accident happened at around 1030 GMT.
No-one was thought to be injured in the other collision an hour before.
The male officers were taken to Ninewells Hospital in Dundee with suspected back and neck injuries but Tayside Police said it was not known whether either collision was weather-related.
Meanwhile, plans to hold one of the largest curling events in Scotland for 30 years have been called off.
It had been proposed to stage the Bonspiel, or Grand Match, on the frozen Lake of Menteith near Aberfoyle next week, but the emergency services said they could not guarantee the players' safety.
Overnight temperatures fell to -19.5C at Braemar in Aberdeenshire and -14C in Aberdeen.
Around Edinburgh the overnight temperature was -11C in Edinburgh and in the Glasgow area it was -10C.
The Met Office said the geography of the area around Altnaharra contributed to the cold temperatures often seen there.
Met Office spokesman Barry Gromett said: "It sits in a glen and there is a lot of snow there, so there is snow covering, long cold nights and no wind.
"It is also in a bowl, effectively with mountains surrounding it, which means that cold air pools down at the bottom.
"Cold air is denser than warm air so it will flow down the mountain and pool at the bottom of the valley."
Hundreds of schools remained closed across Scotland.
All schools were shut in the Borders while most schools in Aberdeenshire and Moray were also closed.
Schools in Highland and West Lothian council areas are not due back until Monday, however Highland Council is due to make a decision about whether the schools will open as planned.
Parents elsewhere are being urged to check their council's websites for local problems.
In the Grampian area, police are urging drivers not to ignore road closed signs after a car crashed into a digger which was helping clear away a previous accident on the A947 near Oldmeldrum in Aberdeenshire.
Meanwhile, European Driving Time regulations have been relaxed for hauliers transporting anti-freeze to airports.
The rules prohibit lorry drivers from working more than 90 hours in a fortnight.
Now drivers will be able to work for 10 hours in every 24, instead of only nine.
Earlier the SNP MP for Moray, Angus Robertson, had said deliveries of vital supplies had been delayed because drivers were having to park up to comply with the restrictions.
The regulations were suspended for the drivers of grit lorries and manufactured animal feed in the past few days.
Councils across the country have reported that grit and salt stocks are low but thousands of extra tonnes are being brought in.
West Lothian Council said it had already used more salt and grit in the past three weeks - 12,000 tonnes - than it usually uses in an average winter.
A spokesman said it was also using whindust and ash for residential streets, which it admitted was not as effective as salt but would help the situation.
And Edinburgh City Council used 100 tonnes of salt on Wednesday night alone.
In East Renfrewshire, thieves are suspected to have used a large vehicle and lifting gear to steal a grit bin with two tonnes of salt from a road.
The bright-yellow fibreglass bin and its load, worth £300, were removed from the junction of Capelrig and Crookfur Road, Newton Mearns, on Thursday.
Elsewhere, farmers' leader Tom Johnston, of NFU Scotland, said hundreds of agricultural buildings had collapsed under the weight of snow across the north and north-east of Scotland.
He estimated the cost of the damage would run to millions of pounds.
The icy conditions have also meant the Scottish Ambulance Service has been struggling to answer emergency calls within its own target times.
Paramedics aim to respond to the most serious emergencies within eight minutes in 75% of cases.
But ambulances only turned up on time in 65% of cases on Wednesday due to the snow and ice and the performance figure was as low as 53% seven days ago.
Scottish Health Secretary Nicola Sturgeon told BBC Scotland the ambulance service had faced a very challenging few days.
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