The UK Health Security Agency (UKHSA) has issued a rare amber weather warning as temperatures are set to plummet in parts of the UK.
The cold weather alert warning of severe conditions in England between 6pm Wednesday and 9am on Monday December 12.
The alert means the cold weather could increase health risks to vulnerable people and it requires social and healthcare services to take action to protect high-risk groups.
UKHSA said air from the Arctic will spread south across the country from late on Wednesday with very cold nights expected as well as frosts.
Wintry showers are also likely in coastal areas bringing risks of icy patches on roads.
The alert reads: "There is a 90% probability of severe cold weather and icy conditions between 6pm on Wednesday, December 7 and 9am on Monday, December 12 in parts of England.
"This weather could increase the health risks to vulnerable patients and disrupt the delivery of services.
"Rather cold conditions are expected to turn colder across much of the UK later Wednesday and through Thursday as air from the Arctic spreads south across the country.
"Very cold nights are expected, with widespread frosts and potentially severe frosts.
"Daytime temperatures persisting near or just above freezing, with overnight temperatures continuing to trend downwards.
"Wintry showers are also likely to affect some coasts, perhaps pushing into some inland areas at times, bringing a risk of icy patches."
It went on: "Look out for friends and family who may be vulnerable to the cold, and ensure they have access to warm food and drinks and are managing to heat their homes adequately.
"Try to maintain indoor temperatures to at least 18°C, particularly if you are not mobile, have a long-term illness or are 65 or over.
"Avoid exposing yourself to cold or icy outdoor conditions if you are at a higher risk of cold-related illness or falls and stay up to date with the latest weather forecasts on the Met Office website."
Agostinho Sousa, Consultant in Public Health Medicine at UKHSA, said: "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.
"Try to heat the rooms you use most, such as the living and bedroom, to at least 18°C if you can, and keep your bedroom windows closed at night.”
Met Office Deputy Chief Meteorologist, Rebekah Sherwin, said: “Temperatures will start to dip this week, with daytime temperatures struggling to get above freezing in many places from mid-week onwards.
"However, the cold air from the Arctic will also bring brighter conditions, with some dry, sunny spells in many areas, particularly away from the coast.”
