The temporary Nightingale hospital in Harrogate, along with those in Manchester and Sunderland could be brought back into use to help with the spike in Covid-19 cases.
NHS England's Professor Stephen Powis told a Downing Street briefing there would also be increased testing of health staff in hotspot areas.
He said: "To protect our staff and our patients we will be introducing - with tests provided by the Test and Trace service - regular testing for staff in these high-risk areas, even when they don't have symptoms.<
"This will help us keep staff and patients in those hospitals as safe as possible.
"Secondly, we have asked the Nightingale hospitals in Manchester, Sunderland and Harrogate to prepare for this next phase.
"They are being asked to mobilise over the next few weeks to be ready to accept patients if necessary."
It will be for local clinicians to decide whether they are used for Covid patients or to provide extra capacity to maintain services for people without coronavirus.