Thousands of NHS operations and appointments are to be cancelled on Monday.
The NHS said patients should be contacted by hospitals to let them know if their appointment is cancelled and patients should not contact hospitals directly.
Some trusts have reported patients cancelling appointments themselves.
Hip replacements and outpatient appointments are among the things being cancelled. Emergency care services will run as normal, as with any other bank holiday.
Covid vaccinations are also continuing with care homes being prioritised.
One man who spoke to the BBC said his stent removal is being postponed until the end of October.
Health leaders said hospitals needed clarity, as there is wide variation in those cancelling appointments and those not.
Prof Philip Banfield, of the British Medical Association, said: "There remains confusion over what NHS services will be provided in hospitals. NHS England must urgently clarify their advice about the services they are expected to provide and how they will be resourced to do so."