Melburnians got their exercise in early at the Tan before the temperature soared into the 30s. Credit:Scott McNaughton Powercor supplies Melbourne's western suburbs and western Victoria, United supplies the southern suburbs and the Mornington Peninsula, and Citipower supplies Melbourne's inner suburbs. "The extreme heat has significantly increased electricity use and this has resulted in localised power outages," Ms Tyner said. "There have also been multiple fuse faults that have affected power." Ms Tyner said the largest fault was along the Bellarine Peninsula, with about 7984 homes without power.

Jasmin Mates found shelter from the heat at IceBar in Fitzroy. She said crews were investigating the cause and were working to restore power across the networks. "We apologise for any inconvenience these outages are causing, particularly during this extreme heat," Ms Tyner said. AusNet spokesman Hugo Armstrong said that as of 9.30pm, about 7500 homes were without power. AusNet look after the city's northern and eastern suburbs as well as eastern Victoria.

"There are a lot fuses blowing in the hot weather and a significant power pull with people having put in air-conditioners they didn't tell us about," Mr Armstrong said. Mr Armstrong said the AusNet outages peaked about 5.30pm, when about 9000 homes were without power. During the afternoon, Phillip Island lost supply for about 30 minutes. Mr Armstrong said extra crews would be working throughout the night to restore power – but it may not be return until 4am. A spokesperson for Jemena said as of 9.25pm, more than 1000 homes across Melbourne's north were without power.

Meanwhile, train services struggled to cope with the sweltering heat on Sunday. As the heat took its toll on the state's transport network, water trucks were used to cool tram lines to prevent them buckling, while bitumen melted on Victorian roads after another hot and humid day. And the demand for emergency services also heated up, with paramedics called to hundreds of jobs around the state. How hot was it? And when can we expect relief? The temperature reached 38.1 degrees at 5.09pm on Sunday.

And there is no relief in sight. Duty forecaster Stewart Coombs said Sunday night was expected to be an "unusually warm, humid night". "It will only go down to 28 degrees, which will make for very uncomfortable sleeping conditions," Mr Coombs said. "People need to remember to stay hydrated, keep in touch with elderly relatives and make sure their pets are also in a cool place and able to access water when they need to." The cool change is not expected to hit until Monday afternoon. "There won't be relief until mid-afternoon tomorrow, around 3pm to 4pm through the city area," senior forecaster Richard Carlyon said on Sunday evening.

"So another hot day to get through [on Monday] with temperatures at 35 degrees." Mr Carlyon said the drop in temperature would be gradual – with the humidity hanging around until Tuesday morning. "It will drop into the mid-20s into Monday evening with a fair bit of cloud cover and rainfall to follow into the night. "Then we'll end up with a 20-degree day on Tuesday and the humidity really drops off then." Man fighting for life after waterslide accident

Ambulance Victoria spokesman John Mullen said paramedics had been called to hundreds of jobs around the state. A man in his 50s was fighting for his life after being pulled from a dam in the Yarra Ranges. Ambulance Victoria spokesman John Mullen said emergency services were called to a private property on Tarrango Road, Wesburn, at 12.15pm after a man suffered a cardiac arrest. It is believed the man was on a homemade waterslide into a dam, when he fell several metres into the water. He was pulled unconscious from the dam and his friends performed CPR on him. Paramedics continued efforts to resuscitate the man until a helicopter arrived and he was airlifted to the Alfred Hospital.

Late Sunday afternoon, the man remained in a critical condition. No major fires Despite the uncomfortable and – for some – dangerous heat, Victorians were spared the catastrophic fires which can accompany hot days. More than 20 CFA firetrucks were called to a blaze in bushland near Tubbut in the north-east of the state. It was contained by about 6.15pm. A CFA spokesperson said on Sunday afternoon that no major bushfires were burning.

Beating the heat As thousands fled Melbourne to escape the oppressive weather, others adopted extreme measures in the city to beat the heat. Jasmin and Terry Mates spent five hours in a Fitzroy bar at -10 degrees. Sitting on kangaroo skins, they donned protective clothing, gloves and ugg boots so as not to literally freeze. Most people last just 30 minutes at IceBar Melbourne, but the couple were keen to hit a six-hour record. And the cocktails helped.

"It's pretty cool," Mrs Mates said. Meanwhile, as the mercury soared, some stores struggled to keep up supply for Melburnians desperately trying to cool their homes. A Kmart in Northcote on Sunday was completely sold out of all cooling devices, from fans to air-conditioning units, its duty manager said. One of those who left the store empty-handed was Northcote woman Elizabeth Watt. "I'd been putting off buying a fan, but with today being a 40-degree day I decided it was time," Ms Watt said.

Unfortunately it wasn't. Ms Watt said she might be forced to sleep on the couch in the living room of her share house – the one room which did have air-conditioning. Trains delayed, replaced by buses Commuters were also affected by the heat. Buses replaced trains on the Hurstbridge line during the day, while the weather also caused minor delays on the Frankston line, Metro Trains said.

V/Line said services to Bendigo, Echuca, Geelong, Shepparton, Swan Hill and Warrnambool were all affected by the heat, with buses replacing trains in several areas and delays expected. Close to record-breaking heat

While it is not quite a record, Melbourne has come close to the hottest-ever January overnight temperature of 30.6 degrees. Melbourne has reached that record twice since records began, once in 1902 and again in 2010. With Jane Gilmore and Liam Mannix