Toxic smog and 'blood rain' set to hit UK as experts urge people to stay indoors

A cloud of dust from the Sahara will hit Britain on Thursday, with eastern areas worst affected

Toxic smog: People with asthma are being warned to stay indoors

A smog alert has been issued for parts of the UK.

A cloud of dust from the Sahara will hit Britain on Thursday.

Southern and central England will be affected, with eastern areas worst hit.

The Department for Food, Agriculture and Rural Affairs (Defra) has issued alerts across southern and central England.

A level-8 red warning is in place for eastern regions with toxic fog and dust threatening to engulf the region.

Health experts have issued emergency earnings to people with asthma and other conditions to stay indoors and avoid exercise.

Warning: Defra say asthmatics should stay indoors

Asthma UK warned of a "perfect storm" of conditions as Britain prepares for a blast of hot air to send thermometers to 17C.

Director of Advice Andrew Proctor said: "People with asthma need to take extra care.

READ MORE: Britain facing hottest Christmas on record - but where will it snow?

"We are facing a perfect storm of asthma triggers, with air pollution and weather changes increasing the risk of potentially fatal asthma attacks for millions of people with the condition

Potentially fatal: Parts of London and the east of England could be affected by the high air pollution

"Two thirds of people with asthma find that air pollution makes their asthma worse, and even more tell us that changes in the winter weather can trigger asthma attacks.

"If air pollution or cold weather makes your asthma worse, do check forecasts and carry your reliever inhaler with you at all times."

It comes as Britain basks in a freakish mid-winter hot spell as forecasters say we could be heading for the mildest Christmas on record.