Australian Paramedics Association (NSW) vice president Scott Beaton says paramedics have unsustainable workloads and ambulance services operate in perpetual crisis.

"We're fighting for the resourcing we need to protect the safety of our colleagues and communities," Mr Beaton said on Thursday.

"We're tired of apologising for arriving to patients hours late.

"We are tired of worrying our patient will be sicker because we can't get there in time," he said.

As a way of saying sorry - and advancing its industrial action - APA paramedics will refuse to take patients' billing details from Monday.

Paramedics will also refuse to move stations from the one where they start their shift, or report on key performance indicators.

Mr Beaton said APA members voted to continue action until firm commitments are made to address demands.

NSW Ambulance Commissioner Dominic Morgan said paramedics were still turning up for the community despite the challenges.

"The amount of cases that NSW ambulance has been going to is genuinely in the unprecedented category," Mr Morgan said earlier in the week.

Pre-pandemic, the NSW Ambulance service would attend about one million calls a year.

Last year there were 1.43 million triple-zero calls - and 116,000 in April alone, Mr Morgan said.

The government has added 300 additional paramedics since January.

Mr Morgan is confident it will be enough to deal with the flu season, which has arrived early and is expected to be more severe than recent years.

Health secretary Susan Pearce said ambulances had been under incredible pressure and urged people to refrain from calling triple zero or going to hospital emergency departments unless it was urgent.

"We have done many things to reduce the pressure on the ambulance service including our virtual care centre," Ms Pearce said on Tuesday.

The virtual care centre provided telehealth services over the phone and online.

The two-week action by paramedics comes shortly before the release of the state budget, with paramedics hopeful they will be able to access increased resourcing and secure a wage rise.

Several public sector workforces have been seeking a pay increase above the 2.5 per cent cap on public sector wage increases that has been in place since 2011.

Premier Dominic Perrottet has hinted at some action in the budget but has warned it is unlikely to fully appease the various unions representing public sector workforces.

Australian Associated Press