Heavy snow and blizzards have led to the closure of many schools in England and Scotland on Wednesday.
Much of the UK has seen snowfall
At least 70,000 children at 300 schools in Scotland are having a day off and more than 100 schools in north east England have also closed.
Schools across Northumberland, Cumbria, Tyne and Wear, Durham, Aberdeenshire, the Highlands and parts of Cambridgeshire have been affected.
Forecasters have said wind chill has made temperatures feel like minus 15C.
Snow up to 15 centimetres (six inches) deep has fallen in Scotland and eastern England with a second band forming over Scotland and Northern Ireland.
Northern England has also seen heavy snowfall while there have been light falls over London and Oxfordshire.
Drivers are warned the biggest danger in many areas will continue to be black ice.
Snow caused severe travel problems across Yorkshire and Lincolnshire overnight.
The M62 westbound was closed when two articulated lorries overturned.
Speed restrictions of 10mph were enforced on other parts of the motorway.
On Tuesday morning one person died and several others were injured when two coaches collided in icy weather conditions.
The Highways Agency is urging drivers to check the weather forecast before they set off and to listen to radio bulletins while they are on the road.
A spokeswoman said many of the UK's motorways and trunk roads had been gritted overnight.
She told News Online: "We're in a constant operation responding to reports as we get them. We've always said we'll do everything we can but there may be conditions where that's impossible."
She said all major routes were clear but warned drivers to take extra care.
Meanwhile, London's tube trains were hit by the icy conditions with many services in open-air parts of the network out of action forcing thousands of commuters to find alternative ways of getting into the capital on Wednesday morning.
Train operators South Eastern, Chiltern and West Anglia Great Northern all reported disruption to services.
A number of airports were also hit by the snow.
Runways at Newcastle Airport were closed for snow clearance and flights in and out of Aberdeen, Orkney, Shetland and Inverness airports were affected.
BBC weather forecaster John Hammond told BBC News Online that a further band of snow over Scotland and Northern Ireland was heading south and would affect much of England and Wales.
Temperatures are expected to rise on Thursday and Friday, but conditions are likely to remain harsh.
A spokesman for AA Roadwatch said that as well as problems on the roads in Scotland and the North, a heavy snow flurry on the M2 in Kent made driving conditions difficult.
Meanwhile, explorer David Hempleman-Adams has urged motorists to carry a sleeping bag, a spade and a flask of tea in their car in case of emergencies.
He told BBC News Online: "As soon as you hit sub-zero temperatures, if you are caught outside, especially if you are elderly, young, or very thin, then your body temperature can fall dangerously if you are not prepared."