St John is urging people not to call 111 unless it's an emergency.
They say they're facing an unprecedented demand as COVID-19 cases rise and put huge amounts of stress on them.
"We're seeing delays of up to 14 hours for non-life-threatening emergencies," says Dan Ohs, St John deputy chief executive.
Last July, St John Ambulance declared an emergency, saying they were unable to handle the demand.
"The current volumes that we are seeing are well in excess of what we saw in July," Ohs says.
Currently, 147 St John staff are unwell. Of these, 66 have COVID-19 and the remaining staff have been shifted around the country to help with shortages.
While life-threatening calls are prioritised, Ohs says some 111 calls needn't be made.
"Some people go to the emergency department, get frustrated with the wait times, go home, and call an ambulance."
Staff shortages are being felt across every essential service - around 200 Auckland transport staff are off sick.
"We had around 1400 services cancelled which is about 10 percent of the network, and that's about double what it was last week," says Richard Harrison from Auckland Transport.
Labs processing COVID-19 tests are also under the pump. But for those who are still waiting for their results, they got an apology on Tuesday from Director-General of Health Dr Ashley Bloomfield.
"We overestimated the number of tests labs could actually process once Omicron took off."
Dr Bloomfield admitted 32,000 tests have been delayed and 9000 have been sent to Australia in an effort to reduce the backlog.
"Anyone who had a PCR test on February 23 or earlier who are still waiting for your result, if you have symptoms still, please go and collect a rapid antigen test (RAT) test from your local testing centre," he says.
But testing centres now handling RATs say it's a logistical nightmare.
"We're unsure if we've got any for the next day, we're unsure if they arrive later in the day, whether we've got enough people to wrap them to get them out the next day," says Awerangi Tamihere from Te Whānau O Waipareira.
But RATs are easing the pressure on lab services - the results are almost immediate.
"Of the nearly 20,000 cases today, only a couple of thousand were PCR confirmed results; the rest were people self-reporting RAT results," Dr Bloomfield says.
There are 100,143 active cases in New Zealand currently, with 64,654 in the three Auckland district health boards.
But it's the Counties Manukau region where Omicron is hitting hardest, with almost a third of all cases in the entire country - 30,801.
