MELBOURNE train commuters endured hot and lengthy delays on Thursday night as the state recorded its highest November temperature.
But it wasn't the heat that wreaked havoc with the city's rail system during the evening peak hour. Rather a bunch of runaway balloons became ensnared in overhead power lines, between Flinders Street and Southern Cross stations, leaving tens of thousands of commuters waiting for up to 30 minutes in the extreme heat.
Other lines on the network had already been hit by major delays, caused by signal and equipment faults.
Ouyen in the Victoria's north-west was responsible for the state's record November high when it reached 45.8 degrees on Thursday. Mildura had its own November record of 45.5 degrees at 3.36pm. The town's previous November high was 45 degrees in 1905.
With summer officially not due to start until Saturday, Mildura has already had a heatwave, with six consecutive days above 35 degrees, including 40 degrees on Wednesday.
The hottest November day in Melbourne was 40.9 degrees in 1894.
Firefighters battled several grass fires, including one in Edenhope in the state's far west that broke out in the morning and covered 12 hectares.
In Locksley, north of Seymour, smoke spread across the Hume Freeway, leading to its southbound carriageway being closed.
Nine fire trucks and two aircraft were sent to deal with a blaze at Talbot, north of Ballarat, the Country Fire Authority said. Small fires also broke out at Picola and Minyip.
At Point Cook in Melbourne's west, building labourers soldiered on. Workers said temperatures in the high 30s were no excuse for a rest.
Plumber Paul Coogans installs solar hot water at six houses a day, and must keep pace with, and work around, other tradies at each site.
After 13 years outdoors he has become used to the heat, but ''you work a lot slower. It's still constant but you just do things differently, like you'll set the panels up in the shade, instead of al fresco, before you go up to the roof.''
Roof tiler Jon Clancy, working on the same Sneydes Road two-storey house as Mr Coogans, said the heat used to bother him when he started as an apprentice three years ago, but not any more.
''You just drink lots of water, wear a hat. Every 10 or 15 minutes, if it's really hot, have a sip, cool yourself, rehydrate.''
Veteran tiler Rod Scherri said the strong breeze made it cooler on the roof than on the ground.
''It can be 38 degrees with a breeze but it's not hot up here, then you get a 40-degree day and there's no wind and you're in big trouble.''
Bricklayer Nathan George worked in the shade for part of Thursday, building the wall of a garage. But later on, shovelling cement into a mixer, he felt the heat and took his top off. He was sipping sports drinks ''to keep the electrolytes up'' and was going to knock off at 2.30pm, a little earlier than usual. ''It's just typical summer,'' he said, although officially summer starts on Saturday.
The Melbourne Ambulance Service attended 25 cases of heat-related conditions across Melbourne up to 4pm, including dehydration, heat stroke and exhaustion.
According to the weather bureau, patchy rain and thunderstorms are forecast for Melbourne for Friday, with a much cooler maximum of 28 degrees. Mildura's top is expected to be 34 degrees.
With RACHEL WELLS, AAP