Hospital operations are being cancelled and people urged to avoid going to A&E as NHS services struggle to cope with demand.
Mid Yorkshire Hospitals Trust said it had seen a 15 per cent rise in the number of attendances at its emergency departments.
The trust, which runs Pinderfields, Pontefract and Dewsbury hospitals, said the figure was expected to increase, and appealed for people only to go to A&E if their condition was urgent.
Patients were having appointments and operations cancelled at short notice, some more than once, because of pressure on the hospitals.
Adrian Griffiths, Mid Yorkshire’s associate director of operations, said: “The cancellations represent less than two per cent of December’s activity.
“All affected patients have been informed, and new appointments have been agreed with those patients affected.”
“We avoid cancelling patients multiple times where possible but without knowing what emergency pressures will be like over the next few weeks there is always a risk of continued cancellation.”
Yorkshire Ambulance Service said last weekend was its busiest ever for “red” 999 calls for the most seriously ill and injured patients.
Ambulance bosses said people should only dial 999 in emergencies when a fast response was critical.
Dr David Macklin, executive director of operations for the ambulance service, said: “We are currently receiving hundreds of 999 calls every day to patients with breathing difficulties and other serious conditions.
“We really need people to use our emergency service wisely so that we keep ambulances available for those patients who need life-saving help”
People with non-urgent problems are asked to call the NHS 111 helpline or visit their GP, pharmacy or the NHS walk-in centre on King Street.