People should open the windows for 10 minutes every hour when friends visit in order to reduce the risk of Covid this winter, a new government campaign launched on Friday says.
A short film showing the impact of opening a window on reducing the level of Covid particles in the air will be released on NHS and government social media channels to encourage the public to ventilate their homes.
The video, in collaboration with the Universities of Cambridge and Leeds, shows how Covid particles expelled while talking linger longer in an unventilated room, increasing the risk of others catching the virus.
Opening a window for 10 minutes an hour when socialising indoors will allow the particles to disperse more quickly, according to the Stop Covid Hanging Around campaign.
Map of UK’s seven-day Covid-19 infection rate, by local authority
Dr Thomas Waite, the Deputy Chief Medical Officer for England, said: "People with Covid-19 release virus particles into the air whenever they speak, breathe or cough, and these can linger in unventilated settings.
"With winter fast approaching and people spending more time indoors, it’s vital everyone understands the importance of using ventilation, such as regularly opening windows – even if just for a few minutes – to keep the air moving and prevent infections."
The Government has previously encouraged people to keep spaces ventilated, but this is believed to be the first time it has issued guidance on for how long, and how often, this should be done.
Dr Helen Lawal, the GP and TV doctor who voices the film, said it was "incredibly important" to take simple actions such as opening your windows "for a few minutes at a time to dilute virus particles that could build up if you have guests that are carrying Covid-19".
With fewer restrictions in place this winter, the act of "refreshing air" in the home when having visitors over is even more important to keep cases down, the Department of Health and Social Care said.
It comes as new research revealed that almost two thirds of the public did not know ventilation was an effective means of reducing the spread of Covid at home. Less than a third are currently opening their windows when they have guests.