Staying home when sick is the "most important" measure advocated by health authorities preparing for a possible converging of a coronavirus pandemic and winter flu in coming months.
Health Minister Brad Hazzard and Chief Health Officer Dr Kerry Chant made an appeal on Thursday for people to observe a number of steps to counter the evolving crisis.
They said NSW Health had planned extensively for a pandemic and further strengthened its response since the SARS, MERS and H1N1 "swine flu" threats, but that "everyone plays a role in prevention'.
"Simple hygiene measures like regular hand washing, sneezing into your elbow and, most importantly, staying home when sick will not only help ease ED presentations for flu but also support existing COVID-19 pandemic plans," Mr Hazzard said.
"Businesses also need to review their continuity plans now. Look at strategies for keeping workers safe with simple measures such as alcohol hand rub in the workplace, stress the importance of staying home when sick, and use technologies that allow people to work from home where necessary.
"We also ask everyone to please see your GP for minor illnesses and injuries where possible, to ensure we keep our EDs for emergencies only, particularly as we head into the busy flu season."
Dr Chant said the emergence of community spread of COVID-19 in multiple countries outside mainland China demonstrated how quickly the virus could pass from person to person because it could present as mild disease.
"Because of this, presenting it's spread can be challenging," Dr Chant said.
"We know from managing past pandemics, including influenza, that unless everyone is onboard from the start - government, business and the community - it makes our task that much harder.
"We have been prudently planning and regularly reviewing everything from ED and intensive care capacity, staff capacity and training and supplies of critical medical equipment to streamlining how we manage patients with acute respiratory illness.
"While the few COVID-19 cases in NSW to date have been mild, the global spread of the virus, coupled with flu season fast approaching, means the situation for our hospitals could change quickly so we're asking everyone to plan now."
Dr Chant said, while the influenza vaccine would not combat COVID-19, it would help reduce the severity and spread of flu.
"Face masks are not recommended for the general public unless you are unwell and masks should be saved for people to use when they are sick," Dr Chant said.