The NHS Nightingale Hospital - built to boost capacity during the coronavirus pandemic - has admitted its first patients.
The first admissions were taken in on Tuesday evening, just two weeks after the temporary hospital in London's ExCel centre was formally announced.
Officials stressed that limits had not been reached at other hospitals across the capital.
A spokesperson for NHS Nightingale London said: "There is also treatment capacity available in other hospitals across London to complement the care being provided at the London Nightingale."
With more than 80 wards containing 42 beds each, the facility has been built to treat Covid-19 patients during the outbreak.
The temporary site has a planned capacity of 4,000 beds to cope with an expected rise in demand.
Watch a timelapse of the NHS Nightingale being constructed:
Prior to the first patients being taken in, the hospital’s chief medical director had said those who are admitted to the hospital will already be on a ventilator and will remain at the Nightingale until their course of ventilation is finished.
It is not known if this is the case for the first patients admitted.
Coronavirus patients suffering from other serious conditions - such as cardiac issues - will be cared for at other specialist centres.
Staff will be able to sleep at nearby hotels once they finish their shift, the hospital’s director of nursing, Eamonn Sullivan, said - though they can also choose to go home.
ExCel centre bosses U-turned on charging the NHS to turn the exhibition space into a 4,000-bed field hospital.
It follows a report in The Sunday Times that the NHS was facing a charge of between £2 million and £3 million per month to use the ExCel centre.
The centre boss said the deal with the health service had included some contributions to costs, but "we have since decided to cover the fixed costs ourselves".
Coronavirus: Everything you need to know