Tens of thousands of Vodafone customers have been left without mobile phone services after an airconditioning meltdown at a major Melbourne switch.
As the mercury peaked at 39.2 degrees at 6pm on Thursday, a spokeswoman from Vodafone confirmed extreme temperatures had caused the failure at the Tullamarine switch which was causing widespread outages.
Spokeswoman Karina Keisler said the failure was affecting about 50 per cent of Victorian Vodafone customers and up to 15 per cent of Vodafone customers nationally. Customers on the 3 network are also believed to have been affected by the outages.
Ms Keisler said the failure meant many customers could not receive incoming calls.
"It appears that calls going out are working but calls coming in are being impacted. I can't tell you confidently because we are still investigating."
She said the failure occurred at 7.45pm and technicians were working to resolve the problem.
"My understanding is that the airconditioning has failed which has created an overheating in the switch and a failure as a result," she said. "I believe it was caused by today's extreme temperatures."
"We've got technicians there and more on the way and we hope to get it sorted as quickly a we can."
But it wasn't the only meltdown.
Melbourne train commuters endured hot and lengthy delays on Thursday night as the state recorded its highest November temperature.
Several lines on the network were affected by signal and equipment faults, however, it was a bunch of runaway balloons that became ensnared in overhead power lines, between Flinders Street and Southern Cross stations, that left tens of thousands of commuters waiting for up to 30 minutes in the extreme heat.
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 St Kilda East, a driver suffered minor injuries when a power pole exploded, causing his windscreen to shatter but authorities aren’t sure if the incident was heatwave-related.
- with Carolyn Webb