Actually I read later that those scales were false and that the temperatures didn't actually reach 50+ in those parts. But then large areas in central Australia are not monitored so it could still be true.
I'm not alarmed by such one off phenomenon. More alarming is how the global average temperature is up 1 degree. Yes, a small amount but these are the amounts that make a difference.
This heatwave would've happened anyway but we are operating in a world that is a whole degree warmer, which exacerbates it.