(Rosie) We're fine at the moment, thanks, other than some pretty severe smoke being intermittently in evidence. That doesn't mean that we are not alert to what is going on around us; the 'local' fires are not all that far from us, and we are practised in packing suitcases and shoving the cat into its carry basket. (CdM) I don't think your comment regarding the mid-forties becoming more common is true - not here anyway. In fact it's not common to have max. temps. at 40ºC. I shall have to dig into my data base to check that, but I am sure that I am correct.
[Dujon] I'm glad that you are OK (at least for now); I do always keep a particular eye out when fires seem to be approaching your neighbourhood. I should know better than to present to you and Rosie a vague impressionistic generalisation about the weather in the form of a fact-checkable statement! Guilty as charged. I suppose it all depends on your definition of "mid" and "commonplace". :) We do know that Australia has just experienced its hottest year on record and in December experienced the two hottest days on record. We had two days above 40 here in Melbourne last month, and while that's certainly not unprecedented, it's definitely unusual for December.
(CdM) Fires are more caused by extreme dryness and the density and type of vegetation than by heat alone though of course heat and dryness are often associated. There have been fires in Britain, nearly always in early spring after a very dry winter. This is the problem of using proxies - some are very sensitive to environmental change whereas others have a multitude of causes and may tell you very little. By far the safest assessment is to use measured and quality-controlled data and proper analysis will tell you if anything's happening. (It is. It's getting warmer)