After a major incident was declared with thousands of Brits unable to cook or heat their homes, the Met Office today issued a warning that a brutal blast of Arctic air could whip through the nation for at least a week.

Large portions of Britain will experience snow showers and ice formation due to the Norwegian cold front, known as the "Troll of Trondheim," with some areas expected to experience temperatures as low as -10C.

Major incident declared with thousands
arctic
(Photo : Ethan Hu/Unsplash)

In London, mayor Sadiq Khan agreed to shelter homeless people in London as part of the capital's emergency severe weather protocol, while racing was canceled at Hexham, Northumbria - with further disruption for sports and on the public transport system expected in the coming days.

After thousands of homes in Sheffield's Stannington neighborhood went without gas and heating for five days, a major incident was declared there.

As the blast of wintry weather continues through the weekend, British Gas anticipates receiving 70,000 calls for assistance with heating this week alone.

In order to survive the cold, public health officials today urged people to prioritize heating their living rooms during the day.

Main rooms should be kept at least 18 degrees Celsius to prevent dangerous conditions, according to the UK Health and Security Agency (UKHSA), which is concerned that cost of living pressures will prevent households from turning on the central heating even though a -9 degree cold snap is predicted.

Many people have already resorted to desperate measures to stay warm, such as spending the entire day in one room, only using the heating once a week, and temporarily insulating walls with cardboard.

A picture of a rural Oxfordshire family's living room, where a pot of pasta is warming up on a wood burner and clothes are drying all around it, was sent to MailOnline.

According to the Met Office, icy conditions with overnight lows in the low-double-digits in exposed parts of the UK could last for at least a week.

The weather forecaster extended the yellow weather warnings from Wednesday into Thursday and Friday, predicting ice in coastal and northern England as well as snow and ice in northern Scotland.

The Troll of Trondheim, an arctic air mass, will quickly move south on Wednesday, engulfing most of the nation by Thursday morning.

Additionally, wintry snow showers could affect England's north and west, and by the weekend, freezing fog is predicted to appear.

Grahame Madge, a spokesman for the Met Office, stated: "We are in this pattern for at least seven days."

There is uncertainty about the evolution and how long it will last, so we might observe it continuing for a while longer.

"However, the pattern for the next seven days is that it will remain cold and we will see double-digit minus figures overnight in areas that are prone to frosts and areas where there is lying snow," the weather service said.

Although wintry showers were anticipated during the cold snap, especially on higher ground and by the coast, Mr. Madge said there was no expectation of widespread, heavy snowfall.

Less moisture is typically present in cold air coming from the north than from the west, which results in less cloud cover and consequently lower overnight temperatures.

Read more: Climate Change: Antarctica and Arctic Simultaneously Experiencing More than 30 to 40 Degrees Celsius Increase in Temperature

People urged to heat main rooms

As a cold snap hits the UK, people are advised to heat their living rooms during the day and their bedrooms before bed, as per BBC.

People who struggle with heating costs or who are unable to heat every room were given advice by health officials.

Snow and ice warnings are in effect for Wales, Northern Ireland, and the east coast as well as overnight lows of -10C (14F) in northern Scotland.

At 18:00 GMT, a level three cold weather alert goes into effect for England.

It was released by the UK Health Security Agency (UKHSA) and is valid until 9:00 on December 12; however, if colder weather is predicted to persist, it may be extended further.

When extremely cold weather is predicted to have a significant negative impact on people's health, especially those who already have underlying medical conditions, the alert is set off.

Northern Scotland is under a yellow weather alert for snow and ice from Wednesday night until Thursday at noon.

A yellow ice warning is in effect for England's east coast from 18:30 until noon on Thursday, when temperatures are expected to drop as low as -3°C (26.6F).

The UKHSA stated that wearing "multiple layers of thinner clothing will keep you warmer than one thicker layer" in addition to heating frequently used rooms to at least 18C.

The agency continued, "Having a lot of hot food and drinks is also effective for staying warm."

Concerns about some people choosing not to use their heating during this week's unusually cold temperatures are being raised by the rising cost of energy.

Related article: Scientists to Bring Extinct Woolly Mammoths Back to Life by Creating 'Arctic Elephant'