An icy blast set to sweep Britain this month could see temperatures plummet to minus 11C, making some areas colder than Iceland – and even the South Pole.

The big freeze has already led to scores of deaths across Europe, with hundreds more being treated for frostbite and hypothermia.

Now the UK is braced for a killer chill which could put more than 2,000 extra lives at risk for every week it lasts.

The Met Office has already upgraded its cold weather alert to Level Three, confirming a 100% probability of “severe” conditions this week.

And experts fear the number of deaths due to the extreme conditions could soar to 20% above normal.

Professor Dame Sally Davies, the Department of Health’s Chief Medical Officer and Chief Scientific Adviser, said: “Mortality rises by 19% in winter months in England, amounting to 27,000 excess deaths or 1,560 more people per week.

OAP warning: Neighbours of the the vulnerable and elderly are being encouraged to keep an eye out

“And very severe weather can substantially add to this death toll.”

During the December 2010 freeze, England and Wales’ overall death rate rose by 21%, from 9,220 a week to 11,193, according to figures from the Office for National Statistics.

Pensioners have been warned to try to stay warm and people are being urged to look after vulnerable or elderly neighbours.

The Army has also been put on standby to help clear snow from key locations such as doctors’ surgeries, care homes and hospitals.

Writing in the Health Protection Agency’s report on the alert, Dame Sally said: “The majority of UK deaths are among older people, especially women, and those with underlying health problems, but they are not people who would have died anyhow at that time.

Not all white: A van stuck on icy Exmoor yesterday

“Cold weather increases the risk of heart attacks, strokes, lung illnesses, influenza and other diseases.

“People slip and fall in the snow or ice causing serious injuries. But in most cases, simple preventive action could avoid illness and injury.”

Around 20% of the overall death toll is generally attributed to cold weather. And in the coming weeks, a wind-chill factor will make temperatures in Britain feel around 3C colder than they are.

The predicted minus 11C compares with a night-time low of minus 6C currently recorded at the McMurdo US research centre in Antarctica.

Arctic toll: The freezing cold has already lead to dozens of deaths across Europe

In the Ukraine, the extreme conditions have resulted in 30 people freezing to death. The country’s Emergency Situations Ministry said yesterday that most of the victims were found frozen on the streets as temperatures plunged to minus 28C in the capital Kiev.

More than 600 have been treated in hospital and 400,000 children sent home as schools were forced to close.

In Poland, 15 people have died because of the cold in the last five days, and one person has died in Russia. In Romania, the death toll has risen to eight since the cold spell set in.

A high-pressure system hanging over Scandinavia and western Russia is pushing biting easterly winds towards the UK, bringing the longest and most treacherous spell so far this winter.

Freezing, but neigh bother: These horses still manage to feed in a snowy field in Merthyr Tydfil

London and the South East was hit by temperatures around freezing yesterday, although snow was limited to light flurries. There were heavier snowfalls in the South West and along the east coast with more on the way.

Temperatures stayed on or just below freezing in Wales, the Peak District and parts of the South West. Lowest recorded was minus 6.2C at Pershore, Worcestershire.

Police in Devon and Cornwall warned motorists against all but essential journeys after heavy snow over areas of Exmoor and Dartmoor.

Exmoor dog walking: But motorists have have been warned against all but essential journeys

In Wales, Devon, Somerset and Hampshire snow was mainly confined to the hills but some lower regions were also hit by falls of up to three inches.

Parts of Scotland were hit by blizzards as temperatures hovered at or just below freezing.

A Department of Health spokesman said: “We advise people to check local weather forecasts for the latest updates. We are working closely with local authorities to ensure vulnerable people stay well and get the help they need within their communities.”

Michelle Mitchell, director-general at Age UK said: “It may have been relatively mild so far this year but winter can be a dangerous time for older people.

“Low temperatures raise blood pressure which puts people at a greater risk of heart attacks and strokes and well as increasing the likelihood and severity of flu and other respiratory problems.”

Tip of the iceberg: Temperatures are expected to continue to drop

Temperatures are set to fall to minus 6C in some areas today – and continue to drop over the next few days.

Clare Allen, a forecaster with MeteoGroup, said: “We’ve got an easterly wind across the country bringing with it snow showers off the North Sea.

“Anywhere that is wet, ice is expected to form – potentially making driving conditions in many parts of the country extremely hazardous.”

Britain's cold snap 'caused by cold westerly winds from Siberia'

Weather conditions are influenced by wind direction, so in winter when the wind blows from the north or east, the temperatures start to plummet.

During most of the winter, the wind has blown from the west.

Over the last few days it has changed to a more easterly flow, drawing air originating from Siberia, which is very cold.

This is linked with a blocking area of high pressure over Russia.

These weather patterns are quite normal and can lead to cold, wintry spells

Clare Allen, a forecaster with MeteoGroup, said: “We’ve got an easterly wind across the country bringing with it snow showers off the North Sea.

“Anywhere that is wet, ice is expected to form – potentially making driving conditions in many parts of the country extremely hazardous.”

Britain's cold snap 'caused by cold westerly winds from Siberia'

Weather conditions are influenced by wind direction, so in winter when the wind blows from the north or east, the temperatures start to plummet.

During most of the winter, the wind has blown from the west.

Over the last few days it has changed to a more easterly flow, drawing air originating from Siberia, which is very cold.

This is linked with a blocking area of high pressure over Russia.

These weather patterns are quite normal and can lead to cold, wintry spells.