A 25-year-old woman found collapsed in the snow next door to where she was staying could have died after falling in sub-zero temperatures following a night out, Kent police have said.
Bernadette Lee was discovered in the front garden of the house next to her sister's by a man walking his dog in Church Meadows, Deal, at 7.30am on Sunday morning.
A man also died following a crash in snowy conditions on the A12 near Kelvedon in Essex at about 7pm on Sunday.
It is believed Ms Lee had no visible injuries and was not wearing a coat when she was found after going out for drinks.
Police investigating her death confirmed they are looking at the possibility she got into difficulties as she made her way home.
A police spokesman said: "There are other possibilities we are looking out but one theory is that this is a tragic accident where a young woman was on her way home from a night out, but she didn't make it to where she was staying.
"We don't know if that was because of the cold, or she slipped or she was drunk or she became ill."
Earlier, police said Ms Lee was pronounced dead at the scene and her death was not being treated as suspicious. A post-mortem examination will be held later this week.
Meanwhile, a Facebook page has been set up, with friends expressing their shock at her death.
One friend, James Tehrani, said Ms Lee was "funny, vibrant, chatty and very much in love with life".
Another friend, Alice Storer, said: "Rest in peace. Such a shock as I was speaking to you last night. A beautiful star in the sky."
The man killed in the car crash was a 59-year-old from the Colchester area, police said. He died at the scene after his car left the road and crashed into a tree on the embankment.
His passenger, a woman of 57, also from the Colchester area, was taken to hospital with serious but not life-threatening injuries.
A teenager who was badly injured while sledging in Middlesbrough remains critically ill in hospital, police said.
Liam Stafford, 16, hit a tree in Flatts Lane Country Park, Normanby, at about 1pm on Sunday.
He was flown by the Great North East Air Ambulance to the James Cook University Hospital in Middlesbrough suffering from head injuries.
East of England Ambulance Service issued a warning after it was called out to treat at least a dozen sledging-related injuries.
While none was life-threatening, some children and adults suffered broken bones or head injuries requiring hospital treatment.
Another warning was given by London Fire Brigade, which urged people to stay off the ice after being called to rescue two men who had fallen through frozen lakes while trying to rescue their dog.
In Kent, a man was taken to hospital with broken bones in his face when he was racially attacked after confronting a group of youngsters throwing snowballs at him.
A young woman who was seriously hurt in an avalanche that killed four of her friends in the Scottish Highlands remains in a critical condition in hospital.
The freezing temperatures and icy conditions have caused further delays and disruption, with more than 5,000 schools closed and motorists being urged to take extra care.
The AA said it was expecting one of the busiest days for call-outs so far this winter, with more than 17,000 anticipated.
The icy conditions caused a school bus with 20 children and three adults on board to skid off the road and down an embankment in Caerphilly, South Wales, just after 9am.
No-one was injured but some of the youngsters, who were aged eight to 12, were taken to a doctor's surgery as a precautionary measure.
As much as 10 to 20cm (four to eight inches) of snow is expected across eastern Scotland and northern England, prompting the Met Office to issue amber warnings which urge the public to be prepared.
Yellow warnings - which advise people to take extra care - are in place for ice and snow expected in South Wales and western England.
"Today's snowiest areas will be northeast England and eastern Scotland," said Sky News weather presenter Isobel Lang.
"Although sleety on the east coast, it will be snow inland, where 10 to 20cm is forecast. Drifting snow, poor visibility and blizzard conditions are likely over higher routes.
"The snow will continue in the northeast tonight and into Tuesday although it should turn drier across northeast England.
"Later tonight and during Tuesday morning the weather is set to deteriorate across the southwest with the potential for some heavy snow across South Wales and parts of southwest England."
The temperatures will not start rising until the weekend, said Lang.
"Until then there will be further problems with ice and snow and daytime temperatures will continue to struggle to climb much above freezing," she said.
"Wednesday and Thursday look largely dry and cold with ice and patchy fog. Friday should see a slow change spread eastwards and westerly winds bring a rise in temperature later and a slow thaw."
On the roads, there have been lane closures on motorways up and down the country, with hazardous driving conditions reported on the M4 at Bristol.
Heavy snowfall closed two major roads across the Pennines, the A628 Woodhead Pass and the A66 between Brough and Bowes. The latter remained closed on Monday evening.
A section of the M6 in Cumbria was temporarily closed after a Land Rover vehicle towing a trailer of bullocks overturned.
Heavy falls in the North East made it a tricky morning commute for many. Northumbria Police said the A68 in Northumberland was blocked, with problems at its junction with the A69.
Drivers were advised to avoid the B6341 at Rothbury and reported a four-vehicle collision on the Spine Road at Cramlington, next to the 3 Horse Shoes roundabout.
Officers also said the A1 in the Newcastle area suffered traffic congestion.
It was another day of snow and ice-related delays and cancellations on the railways.
Virgin Trains warned of cancellations to its services between London and Birmingham and the North West, while services into London King's Cross were also affected.
Eurostar said snow and ice in the UK and northern France were leading to speed restrictions and delays on all its trains. Six services were cancelled with customers told they could exchange their tickets for another date.
South West Trains said it was running a revised timetable because of the weather, and would be concentrating on its mainline services.
The company said there would be no services between Ascot in Berkshire and Ash Vale in Surrey, between Virginia Water and Weybridge, or from Salisbury to Bristol.
Southern said trains were unable to operate between Lewes and Haywards Heath in Sussex or between Horsham and Dorking or Reigate and Redhill in Surrey. The service between South Croydon and Milton Keynes was also suspended.
Planes at Heathrow Airport were grounded for a fourth day and passengers were advised to check the status of their flights before travelling to the airport. More than 200 flights were cancelled - around 10% of the day's capacity.
It came after 260 flights were cancelled at Heathrow on Sunday.
An airport spokesman said: "Because Heathrow runs at almost 100% capacity there is no slack in the system and flights unfortunately have to be cancelled.
"Further cancellations are inevitable given the adverse weather conditions at other airports around Europe."
Flights were also disrupted at Birmingham, East Midlands and Leeds Bradford airports, and at Robin Hood Airport near Doncaster.
Gritters were out in force at Gatwick Airport where there were just two cancellations on Monday morning. However, there were delays of around an hour on the Gatwick Express train service.