Britain's coldest night of the year so far has led to fresh disruption as flights were cancelled, schools remained closed and drivers faced lengthy delays and treacherous journeys.
Vast swathes of the country fell below freezing on Tuesday night - with -13C (8.6F) recorded near Shrewsbury, in Shropshire - and forecasters warned of another "chilly" night to come.
At least 16 flights from Heathrow were cancelled on Tuesday as airlines continued to recover from disruption caused by heavy snow.
A yellow weather warning for ice was on Tuesday afternoon extended to until 11am on Wednesday, covering large parts of Scotland, Wales, northern England, the Midlands, and the eastern coast.
Meanwhile, hundreds of schools in the South West, West Midlands and Wales kept their gates closed for a second day amid the bitterly cold conditions.
In parts of Gloucestershire, 36 homes were without power for a second night after ice and snow caused disruption across the country over the weekend.
Western Power Distribution said the outage was caused by the weather and engineers were expecting to have the power restored by 7.30am on Tuesday.
The AA said it had its busiest day of the year on Monday, with around 25,000 calls from motorists - and was preparing for a deluge of calls on Tuesday.
AA president Edmund King said: "We expect Tuesday to be extremely busy as temperatures plummet overnight, causing even more hazardous conditions on already wet and slippery roads.
"All of our patrols are working hard throughout the country to help those broken down or stuck in ice and snow and we have plans in place to ensure our call operators can travel to and from work safely to answer emergency breakdown calls."
The country also woke up to freezing fog patches with rain and hill snow expected later.
Met Office meteorologist Craig Snell said: "It's still possible that it could go lower but in Shawbury we saw -13C (8.6F) which is the coldest night of the year so far.
"We have to go back to the night of February 13/14 2016 when we saw -14.1C (6.6F) in Braemar for the coldest before that.
"Benson saw -9C (15.8F) and Kew Gardens in London had -4.2C (24F) and Teddington saw -4.8C (23F)."
He added that there was the potential for a "dusting" of snow on higher levels over coming days, and that there was a risk of problems caused by rain falling in already icy areas.
"It will take a good few days for the snow to melt away," he added.
Hundreds of schools closed for second day
Scores of schools were closed for a second day as the cold weather continued to cause disruption.
All council-run schools in Birmingham were shut on Monday following the hazardous conditions, but the blanket closure is not in force for Tuesday.
Nearly 80 schools were listed as closed in Staffordshire, with many citing untreated paths and fears that snow will have compacted into ice as reasons for keeping the gates closed.
Gloucestershire, which saw around 200 schools closed on Monday, will have 80 schools closed on Tuesday, while more than 90 will be closed in neighbouring Herefordshire.
Pupils at 123 primary schools and 25 secondary schools in Shropshire will have a second day off owing to the weather, while in Wales hundreds of schools will be shut on Tuesday, with Caerphilly and Powys particularly affected.
The TUC has called on employers not to force staff to make hazardous journeys into work, saying firms in areas of the country affected by the snowy conditions should have put out advice to their staff on what they should do when snow, ice and a lack of public transport prevents them getting in.
Policies should also cover what parents should do if schools close and they have no alternative childcare, said general secretary Frances O'Grady, adding: "It is essential that employers don't force staff to make dangerous journeys for the sake of presenteeism.
"For many employees the bad weather will have made their commute virtually impossible, but thankfully many bosses now have 'bad weather' policies so staff know what is expected of them."
Are travel services still affected?
Flights
At least 16 departing flights from Heathrow were cancelled on Tuesday as airlines continued to recover from disruption caused by heavy snow.
The UK's busiest airport said its runways were open and fully operational.
British Airways said it planned to operate a "near normal schedule" on Tuesday but passengers due to fly to or from Heathrow were given the option of a full refund or re-booking for travel until December 18.
Airlines had previously said the re-positioning of aircraft and crews from previous days was adding to the problems.
Trains
Rail operators did not report any major disruption due to the cold weather on Tuesday.
However, delays and cancellations across the entire South Western Railway network following a trackside fire at London's Waterloo station on Monday were expected to continue until 4pm.
Six-hour Eurotunnel delays as power supply hit
Freezing conditions have damaged Eurotunnel's power supply, leading to six-hour delays, the company said.
Eurotunnel told customers to cancel or change their plans as Le Shuttle services in both directions between Folkestone, Kent, and Calais, France, have been hampered by what the company called "unforeseen capacity restrictions".
It has warned high-sided vehicles, including lorries and coaches, there could be a wait of up to six hours from the booked departure time, reduced to one hour for France-bound cars and three minutes for UK-bound passengers in low vehicles.
But customers on Twitter complained of waiting times many hours long and said a lack of information had caused confusion.
A Eurotunnel spokesman said: "The residual delays this morning are the aftermath of the horrific weather conditions over the past couple of days, particularly in France where there have been power cuts and road, rail and port closures.
"The tunnel has been running services throughout, but we did experience disruptions due to the weather, especially from the power cuts across the region.
"The delays are currently mainly affecting high vehicles on the passenger service, everything else is back to a normal service. We are working to reduce the waiting time as quickly as possible."
Video: Latest Met Office forecast
Red Cross helps in weather-hit areas
The British Red Cross has been out in force across the UK with teams as far north as Caithness checking on vulnerable people with power cuts, and volunteers in Wales transferring staff and supplies between hospitals in weather-hit areas.
Simon Lewis, head of crisis response at the British Red Cross, said: "Since Friday, our volunteers have been helping medical staff reach patients, and checking on vulnerable people in rural areas, especially after power cuts.
"Our 4x4 ambulances have also provided essential support in these dangerous conditions.
"Our volunteers have shown fantastic commitment to their communities these last few days and I'd like to thank them for their considerable efforts in what have been challenging circumstances."
Weather for today - and rest of the week
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