Temperatures are set to plummet overnight as a health warning has been issued.

Subzero temperatures will roll in on Thursday morning with health bosses are warning people should wrap up warm to avoid having a heart attack or stroke.

Forecasts from the Met Office predict it could feel as cold as -9C tomorrow morning across the region.

The national weather agency uses factors such as wind speed and humidity to determine how cold it will feel.

An amber alert is now in place in Sussex until midday on Friday, January 19 as temperatures begin to go below zero at around 11pm tonight.

Read more: Avoid gritted roads as cold could endanger cats and dogs

They will continue to decrease until 8am, where some parts of the region will see temperatures as low as -4C.

However these temperatures will feel even colder, as atmospheric conditions could mean it feels as cold as -9C.

Dr Agostinho Sousa, head of extreme events and health protection at the UK Health Security Agency, said: "The temperatures we will see leading into the week ahead can rapidly have a serious impact on the health of those over the age of 65 and those with pre-existing health conditions as it increases the risk of heart attacks, strokes and chest infections.

"It is therefore vital to check in on friends, family and neighbours to ensure they are well prepared for the cold weather next week."

In Brighton, "severe overnight frosts" are predicted tonight while in Pulborough, -4C temperatures could lead to icy patches.

The Argus has compiled a list of tomorrow's temperatures below.


Brighton

Lowest temperature: -3C (5-8am)

Lowest 'feels like' temperature: -8C (3-8am)

Chichester

Lowest temperature: -3C (3-8am)

Lowest 'feels like' temperature: -8C (2-8am)

Crawley

Lowest temperature: -4C (5-8am)

Lowest 'feels like' temperature: -9C (6am)

Eastbourne

Lowest temperature: -3C (6-8am)

Lowest 'feels like' temperature: -8C (5-9am)

Worthing

Lowest temperature: -3C (4-8am)

Lowest 'feels like' temperature: -9C (6am)