People have been flocking to the beach

The heat has caused cooling systems in many carriages to break down, leaving passengers sitting on slow trains on plastic seats in 40 degree heat.

"It really is a joke," said one angry traveller. "It's like being inside an oven," said another.

It is even hotter in the Australian outback. In the remote town of Cobar in New South Wales, the mercury rose to an unprecedented 47 degrees Celsius - more than 116 degrees Fahrenheit.

One shopkeeper said stepping out into the street was like "walking into a blowtorch".

Firefighters are on high alert. Bush fires are raging to the north of Sydney and emergency services have introduced a complete fire ban across New South Wales.

National Parks and Wildlife Service personnel have been fighting 13 fires in parks across the state.

Car hazard

As the heat rises, police in Sydney have launched a new campaign aimed at cutting the number of children left in cars by their parents on boiling hot days.

We have had nothing much to cool us down - the cool change fronts keep missing us

Weather bureau spokesman

Inside a vehicle the temperature can be as much as 40 degrees hotter than outside.

Doctor David Schell, from the Westmead hospital in Sydney, says that cars can become deadly greenhouses for anyone locked inside.

"A child can be unconscious in a car within 20 minutes and potentially dead within an hour," he said.

Energy and water companies are struggling to keep up with record demand.

Continued heat forecast

Meteorologists say the heatwave is caused by high pressure systems south of Australia that are bringing hot air from desert areas across the more populated southern and eastern coasts.

They are predicting that the sweltering conditions will last well into the Australia Day holiday weekend.

Hospital receptions are crowded with people feeling the heat

"We have had nothing much to cool us down - the cool fronts keep missing us," a weather bureau spokesman said.

Up to 50,000 people are expected to cram onto Australia's most famous beach at Bondi in Sydney as the heat continues.

Others have taken a more unconventional way to cool off.

One hospital has been swamped by people not needing medical treatment - simply looking to take advantage of its spacious air conditioned reception area. A doctor said it was so busy, there was standing room only.