Thousands of Victorians spent the hottest night in a year without power, with temperatures expected to climb into the 40son Friday.
Many were without power as the temperature struggled to dip below 30C, with about 5800 properties affected by outages on Thursday night.
A spokesman for the State Control Centre said the cause of the outages was under investigation.
The blackouts came after Energy Minister Lily D'Ambrosio urged households to ration their non-essential electricity use.
While "absolutely confident" there was enough energy supply to get through the night, Ms D'Ambrosio suggested turning off dishwashers, kitchen appliances, washing machines and pool pumps.
"What we are asking Victorians to do is just be aware and be mindful that the activities we undertake when we're home do put that further pressure on our energy system," she told reporters on Thursday.
The Bureau of Meteorology has revised its Melbourne forecast to 44C for Friday - the hottest maximum temperature since it hit 46.4C on Black Saturday in 2009.
Authorities are urging people not to take risks during the hot weather, including leaving children in cars or swimming at unpatrolled beaches.
A cool change is expected about 3pm, with a temperature drop of 15C in just 20 minutes forecast for Melbourne.
The sharp change will bring gusts of up to 80km/h, thunderstorms and increased fire risk.
