Bitterly cold weather has hit Kent prompting a warning for people to prepare for many days of freezing temperatures.

Met Office forecasters and health officials have issued a cold weather alert for England for an icy blast which will stretch across the country for the next few days and bring temperatures that are well below average for the time of year.

The level three warning is in place until 9am on Friday, January 20 while there are also a number of yellow weather warnings for snow and ice also in place this week.

Jason Kelly, chief meteorologist at the Met Office, said: "Cold, icy and sometimes snowy conditions are in the forecast this week with the UK seeing more of a north-westerly regime, with temperatures well below average for the time of year.

"Warnings have been issued and ice is likely to be a hazard for much of the week with some tricky travel conditions possible. Maximum temperatures will largely only reach the low single figures with temperatures below freezing through most nights this week."

But why has such an official alarm been sounded in winter and what can people do to keep themselves warm, particularly in the face of rising energy bills?

What is a cold weather alert?

The cold weather alert, sounded by the UK Health Security Agency, is a warning to people that freezing weather is on the way. Warnings range in levels from one to four, depending on the severity of the forecast, with this week's weather warning currently a level three and allocated the colour amber. Four - or a red warning - is the most severe.

The warning also alerts health care and social services to take action where they can to protect those who are most at risk during the cold.

The elderly, the very young, and those with underlying health conditions, particularly cardiac or breathing problems, are among those more likely to become unwell during a very cold snap alongside people with mobility problems and those struggling to afford to heat their homes.

While warm banks or warm spaces have been established in many communities to help people during the day since energy bills began rising, special care and attention will also be paid this week, by local authorities, to those without a permanent home or accommodation, with councils activating Severe Weather Emergency Protocol in order to offer extra help to the homeless.

Alongside the cold weather making worse existing health problems, the direct effects of very cold winter weather can include an increase in incidence of heart attacks, strokes, respiratory diseases such as influenza, falls, injuries and hypothermia.

What's the advice?

While many households are avoiding using their heating because of sky high energy bills - the advice is to try and keep at least one room in your house warm when temperatures plummet.

The UKHSA recommends setting the thermostat to 18C if possible in the room or rooms you're most likely to use.

For those who want to avoid heating their entire property in order to keep costs down, the advice is to keep the radiator on in just one room during the day and switch this off in favour of the bedroom at night, particularly if in poor health or over the age of 65, to ensure there is always somewhere indoors that is on the warmer side.

Other suggestions include keeping all windows closed and wearing several layers of clothing, around the house or at night, rather than just one thick layer to keep out the cold.

Continuing to move around at home, if possible, using hot food and drinks to keep warm and an appeal for the fit and well to check in with more fragile friends and neighbours are also among the details contained in England's cold weather plan which issues advice during expected extreme weather events.

Dr Agostinho Sousa, consultant in Public Health Medicine at UKHSA, added: "Cold weather can have serious consequences for health, and older people and those with heart or lung conditions can be particularly at risk.

"If you have a pre-existing medical condition, you should heat your home to a temperature that is comfortable for you. In rooms you mostly use such as the living room or bedroom, try to heat them to at least 18°C if you can."

Other tips for keeping warm

Keeping houses warm when gas and electric bills are sky high is a daunting task - but there are ways that households can try and keep the cold out.

If the winter sun is shining, the advice is to use it where possible to heat a room naturally, but when dusk hits be sure to close all of your curtains and blinds so that they can act as an additional layer of insulation.

Alongside closing curtains on windows, or even across large patio doors, ensure your home isn't losing heat through mini draughts. In the short term - be aware of poorly fitting letterboxes or open cat flaps, which could all send an icy blast of air through your home and lower inside temperatures.

Reducing airflow is always successful in helping your home warmer for longer as heat cannot escape through open doorways. Therefore if you know you and the family are going to be in the living room all evening for example, closing the door to the rest of the house will help keep it warmer - particularly if there's a number of bodies in there too.

And while the UK Health Security Agency is advising us all to layer up in the cold, rather than wearing one thick item, using hot water bottles under bed covers before climbing in at night can also be another low-cost way to feel warm if your room is cold but these shouldn't be used alongside electric blankets if they're also under the bed and switched on.

Moving furniture away from radiators to allow heat to escape into a room, backing radiators with tin foil to project warm air and using old fashioned draught excluders - or even a rolled up blanket - at the bottom of doors will also all help to both create and trap heat where you need it most.