Australia braced on Monday for the worst conditions since firestorms killed 210 people last month, prompting authorities to send warning text messages to the mobile phones of five million people.
The unprecedented move comes after criticism that warnings ahead of the devastating blazes that hit on February 7 were insufficient, leaving residents inadequately prepared.
With firefighters facing a potentially lethal mix of flames, heat and winds approaching 150 kilometres (93 miles) an hour on Tuesday, Victorian Premier John Brumby said he wanted to ensure warnings reached as wide an audience as possible.
"It's been apparent that some people don't listen to the radio, don't watch TV and don't read newspapers either, so getting that message through the mobile phone will be another way to make sure that people are advised," he said.
Police placed the entire southeastern state of Victoria on alert, not just areas around the four major fires still blazing out of control.
"All Victorians, no matter where you live, need to be alert to increased fire risk and bad weather conditions," police advised, warning the extreme conditions would continue into Wednesday.
The number of firefighters on the ground was bolstered to 4,000 as authorities warned residents to flee their homes early Monday night unless they were prepared to stay and defend them from the flames.
The winds are expected to be so ferocious that helicopters and planes used to water bomb the fires will be grounded on Tuesday as a precaution.
The gales have the potential to send burning embers up to 20 kilometres through the air, sparking spot fires and making the blazes impossible to control.
Authorities also fear they could bring down power lines, sparking new fires, and topple trees already weakened by flames.
Similar warnings were issued about extreme conditions last on Friday but the day passed relatively quietly when conditions proved milder than forecast.
However, Country Fire Authority chief fire officer Russell Rees said there was no room for complacency.
"We are not crying wolf... we are warning the people of Victoria that this situation is very dangerous for us and let me assure you if we do work together we can survive and come through this," he said.
The wildfires have followed a 13-year drought in southeastern Australia which has seen less than four millimetres (0.16 inches) of rain in the state capital Melbourne during the first two months of this year.
Officials say they will remain a threat until April unless rain falls in the parched region.