More snowfall across parts of the UK has brought fresh travel disruption and school closures to thousands.
Severe weather warnings are in place and two walkers have died in freezing conditions in the Lake District.
Councils say they are running out of road salt and the AA warned shortages have created a "road safety crisis".
The M4, M5 and M1 have been badly affected and hundreds of schools have closed. The government said it was hard to prepare for such unusual weather.
The Met Office has issued a number of severe weather warnings for heavy snow in much of southern and central England, Scotland and Northern Ireland.
Some 20cm (7.9in) of snow has been reported in parts of the Cotswolds and Aberdeenshire.
SNOW DEPTHS
Cotswolds: 7.9in (20cm)
Salisbury Plain: 4.7in (12cm)
Oxfordshire: 3.9in (10cm)
Leicestershire: 3.9in (10cm)
Antrim Hills, Northern Ireland: 3.9in (10cm)
Chilterns: 3.9in (10cm)
Bristol: 3.9in (10cm)
Midlands: 4.7in (12cm)
Source: BBC Weather Centre, 1300 GMT
Two walkers have died in the freezing conditions during the last 24 hours in the Langdale area of the Lake District.
The body of a missing walker was found by Mountain rescue teams and another walker died after falling over 100 feet in icy conditions.
The man who fell is believed to have slipped on ice on Pavey Ark in the Langdales near Ambleside. His body has been recovered by an RAF helicopter.
Meanwhile two missing climbers in the Cairngorms were found safe and well. The two men - who are thought to be from the Highland area and aged 22 and 29 - were spotted by a rescue helicopter from RAF Kinloss and are now being flown to Glenmore Lodge outdoor centre.
Matt Taylor of the BBC Weather Centre said the snowy weather would start to ease for much of the UK through the night but with widespread icy conditions developing.
By Friday morning, parts of central and southern England would receive the next heavy snowfall, he added.
Salt shortages
However some councils have just three days' worth of grit left after supplies were "massively" depleted by the heavy snow, the Local Government Association (LGA) admitted. Worcestershire County Council is not gritting roads but sending out snow ploughs.
County Councils in Warwickshire, Wiltshire, Gloucestershire and Ceredigion as well as Swindon borough council have confirmed that they are running low on salt and are only salting main routes.
Hertfordshire County Council said it was seeking additional supplies from abroad, while Cumbria County Council said it could over-spend its winter maintenance budget by £1.3m.
Derek Turner, Director of Networks Operations at the Highways Agency, said it had "three, four days of salt supplies remaining".
Paul Bettison of the LGA told the BBC's Today programme that the UK should look to importing fresh supplies of salt.
"That requires government to actually work with us all, and then we can do it as one - rather than, as we've seen, having this scrapping for what limited supplies are available."
AA President Edmund King called on the government to co-ordinate the situation and ensure salt stocks were maintained so that Britain's roads did not become "death traps".
Rosie Cooper, the Labour MP for Lancashire West, said preparations had been "woefully inadequate" and accused councils of gritting fewer roads each year.
Travel chaos
But Transport Secretary Geoff Hoon said storing snow ploughs and extra gritting salt would be expensive, when the snowy weather is so unusual.
A spokesman for the Highways Agency has advised drivers to take extreme care and not to travel in the worst affected areas unless it is essential.
The Great Western Ambulance Service has brought in 4x4 vehicles to try to maintain their services. The East of England Ambulance Service has asked people to call 999 only in an emergency.
Meanwhile thousands of pupils have had another day off as schools across the UK closed their doors on Thursday.
Some 623 in Wales have shut, while other closures have been reported in Aberdeenshire, Moray, Birmingham, Bedfordshire, Buckinghamshire, Cambridgeshire, Sheffield, Rotherham, Coventry, Warwickshire, Hertfordshire, and Oxfordshire.
Devon, Bristol, Shropshire, Somerset, Lincolnshire, Leicestershire, Northamptonshire, Solihull, Worcestershire, Herefordshire, Staffordshire, Cheshire and Norfolk have also reported school closures.
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