A construction worker battled extreme heat as a heatwave peaked in Melbourne.

Tradie Antonias Roberts was shocked to find the metal foundations of the structures melted under the scorching sun during the 43 degrees Celsius weather in Australia.

Antonias said in the video: 'Early knocked today because of the heat. First time getting knocked off because of the heat. Let's go, baby.'

Health officials warn that extreme heat triggers a dangerous cascade of failure in the body, often leading to fainting, cardiac arrest, or widespread organ failure.

Authorities are urging residents to stay indoors as a record-breaking heatwave continues to grip south-eastern Australia.

As extreme temperatures grip the country, both wild and domestic animals are also facing life-threatening conditions. This has prompted a nationwide coordinated effort from vets, wildlife carers, and the public to combat the effects of heatstroke and dehydration.

The Bureau of Meteorology has recorded temperatures near 50 degrees Celsius in several states, marking an eight-day stretch in which the temperature stayed above 40 degrees Celsius across a vast portion of the inland. This is the longest such heatwave in parts of New South Wales since the 1930s.

Meteorologists said that a stationary high-pressure system has anchored itself above New South Wales. This forces air downwards, causing the air mass to warm rapidly and creating a heat dome over the surface.

The risk of wildfires has also escalated rapidly, raising the fire danger to extreme across 14 districts and prompting authorities to remain on high alert.