Health authorities have issued a yellow cold weather alert for London as forecasters warned that temperatures could plunge below zero later this week.
The UK Health Security Agency (UKHSA) said that cold temperatures could have a “minor impact” on health services and pose a “greater risk” to vulnerable people in the capital.
The alert came into effect at 10am on Monday and will last until 6pm on Saturday.
Cold temperatures, ice and further snow feature on the forecast for the coming days in what the Met Office deemed is the country's "first taste of winter".
The Met Office said that temperatures could drop to minus 2C in London on Friday, minus 4C in Birmingham and minus 7C further north.
An amber weather alert is in place in the East of England, the West Midlands, the East Midlands, Yorkshire and the Humber, the North West and the North East.
The alert warns of a “rise in deaths, particularly among those aged 65 and over or with health conditions”, as well as a “likely increase in demand for health services”.
Within affected areas, there is also a chance of power cuts, disruption to road and public transport and the risk of injury from slipping on ice.
Age UK warned that the conditions could be dangerous for older people.
Charity director Caroline Abrahams said: "With the Met Office issuing a yellow weather warning of snow and ice in some areas this week we are especially worried - the loss of the Winter Fuel Payment has caused many older people to be extra fearful about turning on their heating this winter.
"With high energy bills and food prices it is understandable that some may think they have to cut back on food and turn their heating off, but prolonged exposure to cold temperatures can have a serious impact on an older person's health, especially if they are already trying to manage existing illnesses.
"The cold raises blood pressure, which in turn increases the risk of a heart attack or stroke and breathing in cold air can also increase the risk, and impact, of serious illnesses like flu and pneumonia."
