Mr Fejes said Thursday would be a "hot, unpleasant day" with strong northerly winds. "There will be no sea breezes due to that way-too-strong northerly," he said. "There’s a slight chance of thunderstorms, but not much rain. There could be gustier winds." Fire danger The Country Fire Authority has issued a total fire ban for the Mallee on Wednesday, which includes Mildura and Swan Hill.

Temperatures are predicted to reach the low to mid 40s and northerly winds are forecast between 20km/h and 30km/h. The CFA’s state duty officer Craig Brownlie said the hot and windy conditions could make it difficult for firefighters to suppress a fire. "We are asking people to take heed of the total fire ban conditions," he said. "People need to be aware of the increased fire danger and ensure your fire plan covers all possible contingencies." No fires can be lit in the open air or allowed to remain alight from 12.01am to 11.59pm on Wednesday.

The Department of Health and Human Services has also issued a heat health alert for the Mallee region. Victoria's Chief Health Officer Brett Sutton said the heat alert was issued as temperatures in the Mallee went above the threshold the department considered "potentially dangerous". He urged residents to check on vulnerable people in the community on days of extreme heat. "They include the elderly, people who are pregnant, those with medical conditions, people with a disability and children under five," he said. "It’s also important to drink plenty of water and try to stay in a cool place."

Loading He said if people didn’t have airconditioning they should dress lightly and use a fan or visit a place with cooling, such as a shopping centre. He said people who had appointments during the hottest part of the day should reschedule. "Don’t force yourself to go outside," he said. He also warned not to leave children or pets in cars.

"The temperature can double in a car in half an hour. They can be absolutely deadly in a short period." Mr Fejes urged residents to monitor fire weather apps and look after vulnerable people in the heat. Relief from Thursday's heat won’t come until after lunch. Mr Fejes said predicting when the cool change would sweep through the city was tricky. "It looks like it’s coming through about mid-afternoon," he said. Police have warned they will take a hardline approach to any deliberately or recklessly caused bushfires this summer.

"It might seem like leaving a campfire unattended or operating machinery on a total fire ban day is not a huge issue," Assistant Commissioner Michael Grainger said. "This careless behaviour has the same potential consequences as that caused by arson, easily leading to the destruction of life and property." Police will provide a visible presence, particularly in fire-prone areas on days of elevated fire danger, as part of Operation Safeguard. Anyone found guilty of recklessly or intentionally causing a bushfire faces a penalty of up to 15 years in jail. Lighting a fire on a total-fire-ban day can also attract a fine of up to $37,000 or up to two years in jail.

Transport No service changes are planned on the metropolitan train or tram network. However, Metro Trains and Yarra Trams will keep a close eye on conditions as temperatures increase on Wednesday. Metro can impose speed restrictions on tracks in hot weather. If temperatures on the railway reach 55 degrees, sections of the line or the whole service is slowed to 80km/h.

Loading If the ambient temperature in the city reaches 42 degrees, train speeds are reduced to 70km/h. Trains can run to altered timetables and some services may be cancelled on days of extreme heat. V/Line will replace some trains on the Swan Hill and Shepparton lines with coaches for all or part of the journey due to the extreme heat forecast for northern Victoria. Trains will continue to run as scheduled between Melbourne and both Bendigo and Seymour and on the Albury and Echuca lines.

Department of Transport spokesman Brad Arnoldt says motorists should also prepare for hotter conditions on Wednesday and Thursday, as vehicle breakdowns are more likely to occur in extreme heat. "If you do break down, park in the shade and avoid parking on long dry grass. The underneath of the car can cause a fire," he said. "Before you set off, check your brakes, tyres and oil and water." Beaches Commander Libby Murphy said police would not tolerate anyone engaging in anti-social behaviour on St Kilda’s beach areas after assaults and brawls marred summer celebrations last year.

She said beachgoers would see an increased police presence at bayside locations from St Kilda to Mornington Peninsula as the weather started to heat up, as part of Operation Summersafe. Police will focus on public order, criminal offending and local bylaws including alcohol bans, with support from the Public Order Response Team, water police, the mounted branch and the transit safety division. "Police will not tolerate those who do the wrong thing, engage in antisocial behaviour or put themselves or others at risk,” Commander Murphy said. Alcohol consumption was permanently banned on St Kilda’s foreshore last summer after Port Phillip Council bowed to rising pressure from businesses and police to reduce alcohol-related violence.