Doctors say if new Covid-19 measures fail to work, they could be faced with making drastic decisions about which urgent patients to treat.
The government has announced plans to try to reduce a predicted peak of 1200 Covid-19 patients in hospital a day to 900.
But some doctors said the moves did not go far enough and, even at 900 a day they would still be under huge stress.
Under the newly announced plans, people would have access to free masks from Rapid Antigen Test collection centres, free RATs would be available much more widely and there would be wider access to antiviral drugs.
A campaign to encourage people to wear masks and to stay home when sick was about to begin, but people would not be required to wear masks in more places.
New Zealand Association of General Surgeons president Rowan French said if cases hit 1200, everyone who needed urgent care may not be able to get it, leaving doctors with difficult ethical decisions.
But even at the lower peak of 900, it would be very difficult, he said.
"Where I am, we have got two full [Covid-19] wards and we are just in the process of converting a cardiac ward to a full Covid ward because if we get to 900 that is absolutely going to be required. So, it still leaves things in a fairly desperate situation," he said.
Even though mask mandates were unpopular, increasing the places where masks had to be worn, even just for a couple of months, would help, he said.
There were currently 765 people in hospital.
In the past 24 hours Christchurch Hospital had suspended specialist appointments, Southland and Whangārei hospitals were restricting visitors, and hundreds of people around the country had missed out on operations.
The Ministry of Health hoped the new measures would stop daily case numbers peaking at 21,000 keeping them at 18,000 instead.
Urgent care physician Dr Kelvin Ward said his teams were at their limit and daily cases were about 11,300.
The plan would make very little difference and the government should have been bolder, he said.
"It seems as though it is aimed primarily at making sure the hospital, the health system is not overwhelmed but that is still a huge number of cases - the health system will still be significantly stressed at that level," he said
The free masks should have been the much more protective N95s and there should be more ventilation required in busy indoor places, he said.
Surgeons and specialists were not the only ones cancelling routine appointments.
ProCare GP Jodie O'Sullivan's practice was so busy, it was only taking appointments for half of the day, so it was free to see urgent patients.
It was now up to people to step up and take responsibility when it came to wearing masks, she said.
People should think ahead about the things they wanted and needed to do, like visiting their grandma or going on holiday or to a wedding, and take precautions to avoid getting Covid-19.
All three doctors said urgent steps needed to be taken immediately to hire and train more medical workers.
Whāngarei Hospital emergency medical specialist Dr Gary Payinda said masking was a simple, cheap and effective way of preventing Covid-19 spread and should have been required in schools and workplaces.
"The reality is we never should have let kids go back to school unprotected, let workers go back into crowded densely-packed indoor rooms breathing and re-breathing each others' air.
"I've been using an N95 now for months and months working around Covid and influenza all day every day, working full shifts, seeing lots and lots of infection and not getting sick" - Whāngarei Hospital emergency medical specialist Dr Gary Payinda
"We know that we don't have good ventilation or good filtration. We had a simple cheap easy thing that we could use to prevent Covid spread and that's face masks and we've really failed at it."
Schools and workplaces should also be using CO2 monitors to understand what risk they're facing