Armed Forces personnel have been working 15-hour shifts to help build the new temporary field hospital in east London.
Work to transform the ExCel convention centre into the 4,000-bed NHS Nightingale Hospital began on Wednesday 25 March.
Up to 200 personnel, including infantry from the 1st Battalion, The Royal Anglian Regiment, have been assisting contractors and NHS staff with its construction.
Colonel Ashleigh Boreham, Commanding Officer of 256 City of London Field Hospital, is overseeing the construction of NHS Nightingale.
He said: "It's long hours. It's like what they would normally do on operations.
"It's longer hours than what people are used to working in some parts of the organisation.
“We start at about 7am in the morning and will finish at 10pm at night and we have been here since the start."
He added that all military staff are being rotated, to ensure they have enough time to rest and recuperate.
Following seven days of building work, the facility is set to take in its first COVID-19 patients this week.
Army reservist and chief nurse, Major Eamonn Sullivan, said the work to get the hospital ready has been carried out by a "dream team" of NHS and military staff.
"The book for this hasn't been written, we are writing the book day by day, but what I will say is we've got the right team, the right people," he said.
"We're as ready as anybody could be."
Meanwhile, the Chief Operating Officer of NHS Nightingale, Natalie Forrest, told Forces News the building of the hospital "couldn't have been done without" the Armed Forces.
Alongside the military helping to construct the hospital, there are multiple helicopter bases supporting the NHS up and down the country through medical transports, as well as helping to move medical equipment and personnel where needed.