More than 100 people are set to take part in the first ever 'Leeds Freeze', an event intended to raise awareness about global warming.
At a set time, whatever the volunteers are doing – talking on a mobile, walking up steps, giving directions, eating a burger – they will stop.
Completely. And they will stay like that for five whole minutes.
A similar stunt was carried out in New York's Grand Central Station and caused widespread confusion.
The two people behind the Leeds stunt, Matt Carmichael, 35, and Dr Ron Wiener, 66, are members of environmental pressure group Stop Climate Chaos Leeds.
Mr Carmichael, a drama and English teacher at Roundhay School, said the event would be like a living sculpture. He said: "We're not sure what reaction we'll get yet, but it will be interesting to find out.
"We've put a lot of planning into it and we have over 100 people taking part in at least two locations, possibly three.
"It's officially titled 'The Great Un-freeze: a global warming sculpture' and the reason we are doing it is to raise awareness about global warming.
"All our volunteers will freeze at a certain pre-determined time and then after five minutes, they will just un-freeze.
"They will have leaflets on them about global warming to give to people who might be interested."

Showcase

Stop Climate Chaos Leeds was formed to lobby local councillors and MPs on issues affecting climate change.
It has had moderate success so far, but this is its biggest stunt to date.
The event has been organised as part of the fourth annual Leeds Light Night, a showcase for artistic projects in Leeds and will include a number of other events across the city.
Anyone interested in taking part in the Leeds Freeze can contact organisers on email at: leeds freeze@ yahoo.co.uk.
Log onto www.lightnight. co.uk/leeds to find out more about Light Night.