Victoria enters fourth day of heatwave with cool change to hit Melbourne tonight The cool change is on the way to end the Melbourne heatwave. VICTORIA is bracing for another 44+C day with the much-anticipated cool change not expected to hit Melbourne until 8pm. The extreme heatwave has stretched paramedics to the limit, forcing households to swelter amid power blackouts and commuters to battle transport chaos. Melbourne recorded its hottest day since Black Saturday yesterday, reaching 43.9C. The expected top today is 44C, the last day of the four-day heatwave. It was 36.8C at 10.30am in Melbourne. Bureau of Meteorology forecaster Terry Ryan said the mercury was expected to rise steadily in Melbourne throughout the day to reach 44C by 4-5pm. The cool change will hit Victoria from late afternoon, with the exception of the state's northeast which is forecast to remain about 40C. The heat blast yesterday forced Australian Open officials to suspend matches and about 1000 people were treated for heat stress. The ambulance service has recorded a spike in heat-related cases, with paramedics treating 243 people between Monday and midday Thursday - an eightfold increase. The state has also had a leap in cardiac arrests, with 26 cases on Wednesday and another 28 before 4pm on Thursday. Animals are also suffering, falling from trees due to heat stress on a scale wildlife workers say they have not seen since Black Saturday in 2009. As temperatures hit the mid-40s in most areas, high electricity use and power plant outages put a major strain on electricity supplies, with Victorians using the most power since Black Saturday. Melbourne recorded its hottest day since Black Saturday on Thursday, reaching 43.9C. Friday's forecast is now 44C, the last day of the anticipated four-day heatwave. A packed St Kilda Beach. The ambulance service has recorded a spike in heat-related cases, with paramedics treating 243 people between Monday and midday yesterday - an eightfold increase. Ambulance Victoria manager of emergency management Paul Holman urged people with minor medical complaints not to call 000 as paramedics were under considerable strain. "People should only ever call 000 if they have a medical emergency," Mr Holman said. One of the 000 phone calls we received this week was from someone whose son had a sore throat. Ambulance Victoria paramedics attended 80 cases of heat exhaustion, 28 cardiac arrests and six cases of children locked in cars between midnight and 4pm across the state yesterday. Mr Holman said ambulance responses were up 20 per cent since Monday. Ambulance dispatches with a heat-related code increased fourteen times higher than summer averages. Paramedics also treated about 1000 people for heat exhaustion at the Australian Open. The view of Melbourne's city skyline from Brighton. Picture: Tony Gough Source: News Limited Commuters were gripped by peak-hour train pain for the third day running as Metro urged people to leave work early to avoid major delays forecast due to the "unprecedented" heat. Hot and bothered commuters packed the platforms of Flinders St Station during peak hour as the heat caused delays across all lines. Metro has warned commuters could face a similar transport meltdown today. "It's gonna be a similarly challenging day to yesterday," Metro spokesman Daniel Hoare said this morning. There will be some delays this morning, as we've got some trains still cooling down. Mr Hoare said the train provider would assess the situation at noon before deciding whether to issue a similar plea to commuters as yesterday to leave work early to reduce the peak-hour crush. That worked quite well. People heeded that advice," he said. It took the pressure off the platforms at Flinders St Station. Mr Hoare said trains performed "as well as possible" yesterday, considering the circumstances. But many commuters took to social media to vent their frustrations during the sweltering conditions . Commuters crowded the platforms at Flinders St station as hot weather caused delays and chaos on the city's train services. Colleagues Jamie Shenker and Laura Midgley heeded Metro's plea and left work half an hour early to avoid the crush, but both still faced difficult trips home to Melbourne's southeast. Ms Shenker, 24, said she had arranged for a friend to pick her up halfway home to Ormond rather than contend with bolstered crowds on less frequent trains. "We knew it was going to be hot, so there'd be issues," she said. Major delays on the Pakenham and Cranbourne lines and a track fault which suspended the Stony Point line contributed to chaos across the network. Metro spokesman Daniel Hoare said yesterday's afternoon's peak presented significant challenges for train air-conditioning units. Swedish tourists Alice Karnsund and Caroline Roos cool off in East Melbourne. Melburnians used almost twice their weekly water consumption rate, with households using an average of 255 litres per person, per day - 104 litres more per person than the previous week. But where vulnerable and elderly residents were unable to seek relief, Melbourne councils jumped in to offer a helping hand. City of Yarra spokesman Toby Walker said council agencies had attended to 1100 vulnerable people in the extreme­ temperatures, while Darebin Council distributed pedestal fans to the socially and economically vulnerable.