Leading charities have encouraged the elderly to take “simple precautions” as the country grapples with snow and freezing temperatures.
Age UK said people should not, where possible, try to save money by using less heating, as many contend with rising energy bills.
Large parts of the UK woke up to snow on Wednesday, with the Met Office forecasting further showers over the next few days.
Nighttime sub-zero temperatures are predicted in all four UK nations until at least Friday.
Caroline Abrahams, charity director at Age UK, said: “With much of the UK waking up to snow this morning we are urging older people to do all they can to keep warm and take care.
“With high energy bills and food prices still rocketing it is understandable that many may think they have to cut back on food and turn their heating off, but prolonged exposure to cold temperatures can have a substantial impact on their health.
“Having plenty of hot food and drinks throughout the day can help keep the health risks of the cold at bay, as can taking simple precautions such as wrapping up warm when going outside and sleeping with the windows closed at night.”
John Palmer, director of policy and communications at Independent Age, said cold weather snaps can be “extremely challenging” for some older people, as the temperatures increase the risk of a stroke, heart attack and hypothermia.
He added: “There are ways you can stay warm that don’t use central heating. These include layering up clothes, using electric blankets at night, eliminating drafts by using draft excluders and tucking up long curtains behind radiators, staying active if possible, and visiting warm spaces provided by local councils.”
Dr Agostinho Sousa, head of extreme events and health protection at the UK Health Security Agency (UKHSA), said: “During periods like this, it is important to check in on family, friends and relatives who may be more vulnerable to the cold weather, as it can have a serious impact on health.
“If you have a pre-existing medical condition or are over the age of 65, it is important to try and heat your home to at least 18C if you can.”
Many elderly people will face dealing with the cold and bills by themselves as more than two million people in England over the age of 75 live alone, according to figures from Age UK.
The cold snap comes as energy prices have risen dramatically since last year following Russia’s invasion of Ukraine.
Ofgem, the government’s independent energy regulator, said information and advice for consumers can be found on their website, and that the Energy Bills Support Scheme can provide “valuable extra cash for bills”.
A spokesperson for the ENA, which represents the UK’s energy network operators, said: “We’ve provided information to help at powercut105.com, including what to do if the power goes out.
“The energy networks will be monitoring the weather forecast closely as it develops this week and are ready to take action if needed.”
Forecasters have said in most places the snowfall will continue until Friday, with a yellow warning for snow covering all of the UK north of Birmingham spanning from 3am on Thursday until 6pm on Friday.
A yellow warning for snow and ice also covers London and the south from midnight on Wednesday until 9am on Thursday.