All other regions in England will be under a yellow alert from 12pm on Monday 17 November to 8am on Saturday 22 November.

The UKHSA warned of the increased use of health care services by individuals aged 65 years and over, those with pre-existing health conditions (including respiratory and cardiovascular diseases) and some other vulnerable groups, such as the homeless.

Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, said: ‘This is the first prolonged cold spell of the season, and it is therefore vital to check in on friends, family and neighbours that are most vulnerable.

‘The forecasted temperatures can have a serious impact on the health of some people, leading to increased risk of heart attacks, strokes and chest infections, particularly for individuals over the age of 65 and those with pre-existing health conditions.'

UKHSA has published guidance for professionals protecting vulnerable people and for the public on staying safe during periods of cold weather.

An amber CHA means cold weather impacts are likely to be felt across the whole health service for an extended period of time, with potential for the whole population to be at risk and where other sectors may also start to observe impacts, indicating a co-ordinated response is required.

Surrey and Sussex Healthcare NHS Trust announced on 22 June it had stepdown from the critical incident declared on the previous day due to a surge in demand caused by high temperatures.