Ambulance crews in the Midlands are being prevented from responding to 999 emergencies because they are being kept waiting at hospitals.
In hundreds of cases, paramedics are having to wait with patients in ambulances or on hospital corridors and in waiting rooms for more than an hour because of delays in handing them to nurses and doctors.
Bosses at West Midlands Ambulance Service say the delays are stretching resources and could see crews taking longer to respond to life and death emergencies.
And they have warned it is unlikely they will see any reduction in delays this winter, when ambulance demand will hit its peak.
According to the figures for July, paramedics were delayed 609 times at hospitalsfor longer than an hour. Crews were delayed a total of 11,614 times for longer than half an hour.
New Cross Hospital was the worst hospital in the Black Country for delaying paramedics over an hour, with 45 incidents. The hospital had a total of 680 incidents of crews waiting more than half an hour.
Sandwell General Hospital kept crews waiting 26 times for longer than an hour and 558 times for longer than half an hour.
Russells Hall Hospital in Dudley delayed paramedics 18 times for longer than an hour and 884 times for more than half an hour.
At Walsall Manor there were a total of six incidents when emergency workers had to wait longer than an hour, and 412 incidents involving delays of more than half an hour.
Stafford Hospital kept crews waiting 12 times for longer than an hour, and 204 times for longer than half an hour.
Paramedics have to wait with patients whose injuries are not deemed life-threatening but who cannot be left alone. These include fracture patients and those who require monitoring or drugs. Recorded waiting times for hospital A&E departments to do not start until the patient is handed over by the paramedic.
Anthony Marsh,chief executive of the West Midlands Ambulance said: "We could all be doing more, we are all determined to do more."