The region's public health director has urged residents to be aware of their own health, and to check in on vulnerable family, friends and neighbours with the smoky conditions set to continue.

Curtis Gregory said there were 828 respiratory-related presentations to Illawarra Shoalhaven Local Health District EDs in November.

He said the figure was slightly higher than the usual number of presentations at the same time of year.

"However, it is important to note that these figures represent all respiratory-related ED presentations, as we do not have specific data on smoke-related presentations," he said.

Across the state, presentations to EDs and calls for NSW Ambulance assistance for asthma or breathing problems were higher than normal for a third straight week. For the week to December 6, there were around 1140 ED presentations, about 25 per cent more than the usual weekly average of around 900.

The largest increases were in South Western Sydney Local Health District, which serves the region particularly affected by smoke last week.

NSW Ambulance fielded around 2330 calls in the same period, around 30 per cent more than the average for the week of 1780.

Mr Gregory said those with respiratory conditions should avoid outdoor physical activity when there's smoke around, and people with asthma should also follow their action plan and keep their relieving medication on hand.

"People with heart and lung conditions, as well as vulnerable people including pregnant women, older people and younger children, should limit the time they spend outside," he said.

"Healthy people may experience eye or throat irritation and a runny nose, but for the more vulnerable the symptoms can be far more serious.

"These include wheezing, coughing and chest tightness, as well as increased difficulties with breathing which may prompt an asthma or bronchial attack."

He advised people to stay indoors with doors and windows shut, in air conditioning if possible, to keep hydrated and seek medical assistance if required.

"It's also important for people to be aware of others in the community who might be more vulnerable and keep an eye on them," Mr Gregory said.

With more people starting to wear face masks, NSW Health also advised them to make sure they used the correct ones. Bushfire smoke contains very fine PM2.5 particles, which are so small they pass through most types of mask.

"A P2 mask does filter out these particles, but is only effective if there is a good fit and an air-tight seal around the mouth and nose," Director of Environmental Health Dr Richard Broome said.

"Evidence shows that this is difficult to achieve in practice, so they may not provide the benefit people are hoping for."

In case of emergency, dial Triple Zero.