A cool southwesterly change is moving across Victoria, reducing the catastrophic fire risk that has forced people from homes and campsites.

Australia is cooling down after another day of deadly heat with temperatures in three states soaring into the 40s, including record highs in Melbourne.

A long spell of dry weather is likely to lead to more fire bans being put in place.

Firefighters were this evening still dampening down hotspots after a major fire at an Auckland lighting firm opposite St Lukes shopping Mall.

The blaze broke out at 10.45am at Modus Architectural Lighting in Wagener Place, across the road from St Lukes Mall.

Firefighters battled a blaze at a massage parlour in central Auckland this afternoon.