Extreme heatwave conditions can be difficult to cope with. It is all explained here.
This is how the explanation starts:
“For the first time, the Bureau of Meteorology has provided a national definition of a heatwave.
Many Australians have kicked off the new year in sweltering heatwave conditions, with the mercury soaring to record-breaking temperatures in several states.
The bureau says heatwaves have taken more Australian lives than any other natural hazard in the past 200 years, but until now it had not given a national definition of just what constitutes a heatwave.li
A heatwave is now defined by three or more days of unusually high maximum and minimum temperatures in any area.”
To read more, please find the link under ‘here’ at the top of this page.
AuntyUta 
I think it’s clear that I have accurately used the term “heat wave” in the past. We have three-day unusual bouts of heat several times a year! And they are indeed killers. Ours usually occur in early fall, even more than summer. On the heels of your fires, you don’t need heat waves! Whew!
Last October, when there were fires over vast areas of Australia,, we in the Illawarra also had some enormous heatwaves. And this was not even summer yet!
Here, in the Illwarra, we had temperatures in the forties (we have Celsius), but no fires close to where we live, which was lucky.
Since then the Illawarra has not had any real bad heatwaves, but there are a lot of other parts of Australia who still keep getting extremely high temperatures..