People urged to heat main rooms as cold snap begins
People are being advised to heat living rooms during the day and bedrooms before going to sleep as a cold spell hits the UK.
Health officials issued the advice to people who cannot heat every room or are struggling with heating costs.
Overnight lows of -10C are predicted in northern Scotland with snow and ice warnings there, in Wales, Northern Ireland, and the east coast.
A yellow weather warning also applies to Wales and most of Northern Ireland from midnight until 18:00 on Thursday.
This abrupt change to cold winter weather will come as more of a shock to the system, given that this autumn has provisionally been the third warmest on record in the UK, in which frosts have been very rare.
Rising cost concerns
The UK Health Security Agency (UKHSA) said that, as well as heating rooms that are used the most to at least 18C, "several layers of thinner clothing will keep you warmer than one thicker layer".
"Having plenty of hot food and drinks is also effective for keeping warm," the agency added.
The rising cost of energy has prompted concerns that some people may resist using their heating, even during the unseasonably cold temperatures expected this week.
Under the current energy price guarantee, a household using a typical amount of gas and electricity can expect to pay £2,500 annually. This rises to £3,000 a year for typical use from April.
Dr Agostinho Sousa of the UKHSA said: "Cold weather can have serious consequences for health, and older people and those with heart or lung conditions can be particularly at risk.
"If you have a pre-existing medical condition, you should heat your home to a temperature that is comfortable for you."
Disability charity Scope said a survey of 1,000 disabled households suggested 43% had cut back on electricity and gas, with some saying they were switching off heating and using duvets to keep warm.
Additional support to help with energy costs is available for the most vulnerable, alongside a one-off £400 discount for all households.
Fuel poverty charity National Energy Action called on the government to "step in with more help for those at greatest peril this winter".
