Lake Macquarie and Central Coast have been pinpointed as high-risk areas for heatwaves owing to their higher number of older residents.
A University of Newcastle research team ranked the areas in preliminary studies into heatwave risk over the past two decades.
Associate Professor Danielle Verdon-Kidd's research team has been awarded a $1.3 million federal grant to continue its research into heatwaves.
The grant, from the government's Disaster Ready Fund, was aimed at improving preparations for "the escalating threat of heatwaves in regional NSW".
The three-year project will rank local government areas on "current and future heatwave risk".
National health data shows at least 473 heat-related deaths were reported to a coroner in Australia from 2001 to 2018.
Of these, 354 deaths occurred during heatwave conditions, including 244 in buildings.
The University of Newcastle researchers will work with councils in high-risk areas with a "high population of vulnerable people".
The findings will inform the co-design of resilience strategies and "tailored heatwave preparedness plans".
A/Prof Verdon-Kidd said the research was "about getting NSW prepared for what's to come".
"Under climate change, we've already seen an increase in heatwave severity and frequency across certain regions over the last two decades," she said.
This was projected to "continue into the future".
"We've got regions that haven't been exposed much to heatwaves, but it's becoming more of an issue for them.
"Other regions that were already exposed to heatwaves, they're getting worse."
In August, Nobbys recorded a monthly mean maximum temperature of 20.4 degrees, the fourth highest figure for that month in a century.
A/Prof Verdon-Kidd said the data on temperature rises was clear.
"We've seen year to year rises in temperatures," she said.
"Temperatures are increasing pretty much everywhere across the world."
She said the seasons were changing and "it's getting warmer earlier".
"Spring is occurring earlier - that's impacting our agriculture. So we can get earlier heatwaves, and heatwave season is projected to extend as well."
Of all the variables of climate change, temperature data gave researchers the most confidence in understanding the unfolding situation.
"There's a direct relationship between carbon dioxide, the atmosphere and global temperatures," she said.
A/Prof Verdon-Kidd said Blacktown City Council was a good example of how to adapt to heatwaves, adding that communication was crucial.
"They activate cool spaces and tell residents where to go to stay cool."
This was particularly important for "some of the elderly community who can't afford or don't have air-conditioning".
Systems would be needed to monitor these people's health and help them get to "a cool shopping centre or library for example" when needed.
"In the future, we will have that in-built into each local government area's strategy, so everyone gets the message about where to go to keep cool," she said.
"And also what people should do if they're starting to feel unwell."
Gardens and more trees were an important part of the equation.
"The heat island effect is a separate, compounding issue. Built-up cities are heating up faster," she said.
