Cardiac arrests and heat exhaustion cases in Victoria soared on the third day of temperatures above 40C.
Ambulance Victoria figures show there were 163 cases of heat exhaustion on Thursday and 37 cardiac arrests.
There were also nine reports of children being left in cars.
Reports of heat exhaustion and cardiac arrests have steadily increased since Tuesday.
By noon (AEDT) on Friday, there were 30 heat exhaustion cases and the number of cardiac arrests was already at 37.
Melbourne has broken a record for having four consecutive days above 41 degrees.
By 1.25pm it had already reached 41.5C at Melbourne Airport.
Temperatures are forecast to hit 44C.
The record-breaking stretch comes a day after Melbourne recorded its hottest day since Black Saturday, reaching 43.9C on Thursday.
The mercury is also tipped to rise to 44C in Horsham near the Grampians on Friday, with the chance of a late storm.