From CNN's Mick Krever and Nick Paton Walsh in London

Work continues at the ExCel centre which is being made into a temporary hospital in London on March 31. Stefan Rousseau/Pool via AP

The UK will open the doors this week on what could soon be the biggest intensive care unit in the country -- and it was built in about a week.

As the number of Covid-19 cases in the UK began to rise, the National Health Service (NHS) realized it might be short many thousands of ICU beds.

It hopes the solution is at a massive convention space in London’s East End.

The ExCel Center is more accustomed to showcasing the latest ventilator technology than actually using it.

The coronavirus field hospital will be called NHS Nightingale, after the pioneering nurse Florence Nightingale.

“Oh my goodness, there is no comparison,” says Natalie Forrest when asked about the hospital’s scale.

She is the operational guru responsible for transforming empty halls into a functioning hospital.

When fully running, it will have 4,000 beds. At the moment, just a few dozen that CNN saw were ready.

“Obviously we don’t want to use those beds,” Forrest says.

It’s staff, rather than equipment, that medical director Dr. Alan McGlennan says he’s most nervous about running out of.

“Critical care nurses are in very short supply,” he said.

It won’t be a hospital in a traditional sense. There will be no front door, no waiting rooms. “We will be receiving patients from ICUs across London,” Forrest says.

“So not all types of patients -- just patients who are sedated and ventilated, and need to be cared for in an ICU.”

Britain has more than 25,400 coronavirus cases, with nearly 1,800 deaths, according to figures compiled by Johns Hopkins University.