Politicians, experts and officials walk a fine line with public health emergencies.
They want to get the public to take it seriously and take precautions, but not to panic.
They want to show plans and measures are in place to slow and contain the threat, but also don't want to provoke an over-reaction.
At times like these, with the Covid-19 coronavirus at large in the world, people look to the authorities for protection, expertise and competence.
Prime Minister Jacinda Ardern's approach to news of New Zealand's first confirmed case, a person returning from Iran, was to urge calm.
People were told not to toss routine aside and to go "about their daily lives". It's the same language used to dampen fears after urban terror attacks.
Ardern added: "If you need a bottle of milk, go and get it. If you don't, do not react in any other way than you would any other day."
If careful planning, an ability to adapt and good information channels keep the outbreak to a few isolated cases, people will have confidence that authorities know what they're doing.
We could be in worse hands. In the United States, President Donald Trump on Saturday used the word "hoax" when talking about the coronavirus. "They tried the impeachment hoax. This is their new hoax," he said of Democratic criticism.
Hoax is a dangerous word to bandy about when people need to come forward to seek help.
Trump was likely spooked by a market downturn, which placed a question mark over his argument for re-election — a well-performing economy. Yesterday he announced the first death in the US from Covid-19 and more travel restrictions. He also denied trying to minimise the virus.
A combination of a careful official response — checks, quarantines, tracing source infection — and public awareness seems the best way to deal with it.
Cases of Covid-19, which is spread by droplets, are appearing in dozens of countries. World Health Organisation data shows that most new cases outside China were sourced locally or traced to a non-China country. People are now getting it without overseas travel or a link to a previous case.
The lack of a vaccine, the economic toll around the world and sudden travel restrictions are major concerns. Yet a Chinese health report found most cases were mild infections and the number of cases outside China is tiny considering the many millions living in those countries. Of the about 85,000 cases worldwide, about 80,000 have been in China. South Korea, Iran and Italy are dealing with the biggest outbreaks.
People can practise good health protection to limit their exposure. Experts say to regularly wash hands with soap for 20 seconds, to avoid touching your face and to keep a safe distance from people coughing and sneezing.
The people most at risk are, unfortunately, those on the front line in any deadly flu season — people in hospitals, the elderly and frail in rest homes, and healthcare workers.