ITV News reveals evidence that A&E departments are under unprecedented strain this summer.
National performance, measured by the target that 95% of patients should be dealt with in under 4 hours, shows a clear deterioration in May and June this year compared to the same period in the previous four years.
It is not unusual for the target to be missed when winter creates pressures between December and April. But between May and November performance hasn't fallen below the target for a single week since 2010, until this summer.
The immediate cause is an unexpected rise in people arriving at A&E. Aside from a dip in the first week in June, attendance figures have grown week on week, at a time of year when hospitals usually expect a period of post-winter respite.
What is causing the rise in attendances is less clear. ITV News has spoken to two hospital chief executives.
One reports there is no discernible pattern: patients are of all ages, and have a whole range of different medical conditions.
The other chief executive believes it is the frail elderly and those with complex conditions, who are presenting as emergencies this year even though warmer weather usually sees their numbers fall.
Neither manager attributed the rise at their hospital to people seeking help at A&E instead of going to their GP or out-of-hours service. The rise they are coping with is a rise in people needing hospital treatment, they say.
The Department of Health told ITV News:
We know some parts of the NHS are running hot at the moment because of near-record attendances. We are supporting the NHS and have recently pledged an extra £400 million to ease pressures.