Victoria set to swelter, finally SUMMER is set to finally arrive in Melbourne, with the mercury tipped to reach 40C for the first time this season. Victorians will sweat through three successive days of 30 degrees or higher from Wednesday with the temperature expected to top 40 degrees in some parts of the state including Melbourne on Thursday. Those in the Mallee region will be hit hardest as forecasters predict three 40-plus days in a row for Victoria's northeast. Australian Medical Association Victoria president Dr Stephen Parnis on Tuesday warned parents not to leave children unattended in cars during the heatwave, even with the windows down. "This is a criminal offence in Victoria as it can have fatal consequences," Dr Parnis said. Never leave children or pets unattended in cars, not even for a short period. It's not worth the risk. Temperatures inside a parked car can be as much as 20 or 30 degrees higher than the outside forecast. Bureau of Meteorology senior forecaster Terry Ryan said Victorians will swelter through a warm Thursday night before relief arrives around midday on Friday.