A cold weather health alert has been issued for most of the country as temperatures have dropped below zero in the last couple of days.

Temperatures are set to drop to -4C overnight in some parts of Sussex after light snow fell across Sussex yesterday morning for the first time of the season.

There were reports of black ice in the Crawley area this morning, causing dangerous driving conditions.

The yellow alert, issued by the UK Health Security Agency (UKHSA) and the Met Office, is for the South East, the South West, the East of England and London.

It warns that temperatures may become challenging for some and lead to increased risk for vulnerable people and is set to end on Tuesday, December 5.

It reads: “Conditions across the UK are forecast to turn increasingly cold toward the weekend and into early next week. Overnight frosts will be sharp and widespread with only limited recovery of temperatures by day.

“There is some uncertainty over the longevity of low temperatures, but a protracted period into next week is currently the most likely solution, before turning milder from the middle of the week.”

There is also an amber cold health alert in place for the East Midlands, West Midlands, North East, North West and Yorkshire and the Humber.

Dr Agostinho Sousa, head of Extreme Events and Health Protection at UKHSA, said: "With a risk of widespread overnight frosts and some snow across the country this week, it’s important to check in on the wellbeing of those most vulnerable to the cold.

"Cold weather can have a serious impact on health, particularly older people, and those with pre-existing health conditions, as it increases the risks of heart attacks, strokes, and chest infections.

"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 in, such as your living room or bedroom."