Health officials have issued a cold weather alert for England as temperatures across the UK are set to plummet from Saturday.
A cold snap is set to hit much of the country, bringing temperatures several degrees below average, with a brisk wind across much of the south.
In London, temperatures will dip to a chilly 5C on Sunday and 4C on Monday and Tuesday, but the frosty weather comes with clear and dry conditions, the Met Office said.
The UK Health Security Agency (UKHSA) urged drivers to be cautious of ice and added those with vulnerabilities should try and heat the main room in which they will be staying.
Dr Agostinho Sousa, UKHSA Head of Extreme Events and Health Protection, said: "Cold weather can have a serious impact on health, particularly for older people and those with pre-existing health conditions, as it increases the risks of heart attacks, strokes, and chest infections.
"Temperatures are expected to turn particularly cold overnight, as we would expect at this time of year, so if you have a pre-existing medical condition or are over the age of 65 it is important to try and heat the rooms where you spend most of your time, such as your living room or bedroom, in the coming days."
The warning, which covers all of England, states it is "probable" that the cold spell could last into next week. It is in place between 9am on Saturday and expires at noon on January 12.
Met Office forecaster Jason Kelly said that while the weather is expected to get colder, it is also expected settle, in contrast to Storm Henk’s strong winds and heavy rain.
"Clearer skies and a marked reduction in precipitation are expected, although any showers that do occur are likely to be wintry in nature," he said.
"A combination of overnight freezing temperatures, saturated ground and calm winds mean increasing risks of frost, fog and icy conditions."
It comes as more than 1,000 properties were flooded across England due to heavy rains.
Hundreds of local flood warnings and alerts remained in place on Friday, while the Environment Agency said "significant river flooding impacts" were expected on Friday and Saturday across parts of the Midlands on the River Trent and in Gloucester.
In London, canal flooding in Hackney Wick led to knee-deep water in houses, with residents on Friday telling of the damage.
Residents at around 100 affected properties on Dace Road, Wick Lane and Smeed Road were bailing out water by the bucket-load on Friday morning.
One resident, Simone, who didn't want to give her surname, said: "I was in the gym and I came back to my flat. [Water] was up to my knee high. It was crazy."
