'Incredibly difficult' winter for NHS Wales staff
The proportion of patients spending less than the four hours target time in hospital A&E departments in Wales is the lowest since records began.
The percentage waiting more than 12 hours in A&E is also the highest, according to the health figures for February published Thursday.
The 38,323 emergency calls to the ambulance service were also the second highest on record.
But response times to "red" calls remained within the 65% target at 69%.
The worsening performance figures in Wales is also reflected in other parts of the UK too.
Vanessa Young of the NHS Confederation in Wales - which represents health boards and hospitals - said it had been a difficult period for staff.