NHS England publishes weekly reports which reveal whether hospital trusts are struggling to manage during the colder months, based on key indicators.
This is how Oxford University Hospitals NHS Trust coped from January 14 to 20.
General and acute wards at Oxford University Hospitals were 95.3% full on average, well above the safe limit of 85% recommended by health experts.
The occupancy rate has remained mostly unchanged since the previous week.
British Medical Association guidelines state "to ensure safe patient care, occupancy should ideally not exceed 85%". According to NHS Improvement, occupancy rates of 92% and above lead to significantly worse A&E performance.
The BMA also raised concerns about the number of available beds needed to cope with winter demands.
On average, Oxford University Hospitals had 930 available beds each day, of which 886 were in use.
According to NHS Improvement, a higher proportion of long-stay patients can impact the ability of hospitals to accommodate urgent admissions and manage bed capacity.
At Oxford University Hospitals, 443 patients had been in hospital for a week or more , taking up half of the occupied beds.
Of these, 172 patients had been in hospital for at least three weeks, making up 19% of all occupied beds.
A total of 806 patients were taken by ambulance to A&E during the week. That's a rise in emergency arrivals compared to the previous week, when 770 patients were brought by ambulance.
Delays left 30 patients waiting 30 minutes or more before they could be transferred.
NHS Improvement guidance states that ambulance crews should hand patients over to A&E staff within 15 minutes of arrival.
Any delay in transferring patients leaves ambulances unable to respond to other emergencies, as well as risking their patients' safety.
Delays affected more patients than the previous week, when 20 patients waited more than 30 minutes to be transferred.
Norovirus, the winter vomiting bug, is highly contagious. Outbreaks spread rapidly through hospitals, causing staff to close beds to prevent infection spreading.
But at Oxford University Hospitals, no beds were closed due to norovirus outbreaks - both during the most recent week and over the previous one.