Experts are warning that over 2,500 people in England and Wales are likely to have died in the past week as a direct result of the cold weather.
The elderly are most at risk
BBC News Online looks at why cold weather is linked to extra deaths.
Who has issued this warning?
The Met Office and the Faculty of Public Health have made the calculation based on the drop in temperature over the last few days.
Are these people who will definitely have died?
No. The figure is a prediction. But in previous winters, (between December and March), between 24,000 and 49,000 extra people have died compared to non-winter periods.
What do people die from?
Half of the excess deaths caused by the cold are from strokes and heart attacks.
The cold temperatures thicken the blood, making people more susceptible to these conditions.
A third of the deaths are from respiratory diseases, such as bronchitis and pneumonia.
The viruses which can lead to these conditions thrive in the colder winter months.
Flu usually only accounts for a tenth, with hypothermia responsible for less than 500 winter deaths each year.
The elderly, the disabled and other vulnerable groups are most at risk.
If these deaths are linked to cold weather, why don't we act to prevent them?
Each winter, a larger proportion of Britons die because of the cold than in either Finland or Russia.
This is despite temperatures there being around twice as cold as in Britain.
Experts say we have such a poor record because there is a lack of preparation for the inevitable cold weather.
They say many of the deaths would be preventable if people kept warm inside, ensuring their houses were properly insulated and heated.
Around three million households in the UK are estimated to be in "fuel poverty" - where more than 10% of household income is spent on keeping the house at an adequate temperature.
Wrapping up well outside and having a flu jab also help protect against illness.
So what can be done?
Professor Sian Griffiths, president of the Faculty of Public Health, said: "It's recognised as a problem. There is a government target to reduce fuel poverty.
"But we need to do more to reduce the impact of cold on health.
"We need to make sure houses are well insulated and everything we can do to stop these deaths is done.
"We also need to ensure that vulnerable people themselves take what steps they can to help themselves, such as wrapping up well.
"And we need to make sure that health professionals are aware of the potential risks of the cold so that they do not, for example, discharge someone out of hospital into a cold house."