Searchers will be battling the heat as they search for August ‘Gus’ Lamont.

Gus Lamont: Temperatures set to soar on day two of renewed search for missing outback child

Searchers will battle temperatures of up to 36C to find further clues.

The desperate search for missing four-year-old August “Gus” Lamont has entered a critical new chapter, with fresh boots on the ground on day two of the renewed search in South Australia’s unforgiving outback.

Eighteen days have now passed since Gus vanished from his grandparents’ remote sheep station near Yunta, with personnel from police and Australian Defence Force returning to the property — this time with a new strategy, new search zones, and a new taskforce.

Gus was last seen playing on a mound of dirt just 500 metres from the homestead about 5pm on September 27. When his grandmother called him in half-an-hour later, he was gone.

What followed was one of the largest land searches in South Australian history — more than 60,000 hectares scoured by foot, vehicle, drone and helicopter. But despite the scale of the operation, not a single confirmed trace of Gus has been found.

A second footprint once thought to be a breakthrough was ruled out last week, leaving investigators with just one clue: a single footprint discovered on September 30, near the homestead.

“It’s been searched. Gus is not there,” former SES volunteer Jason O’Connell told 7NEWS.

He was granted police approval to use his tracking skills alongside Gus’s father.

“I just don’t get how he vanished like that. My heart breaks for the family.”

ADF personnel are joining the search for August Lamont at Yunta in SA’s Mid North ADF personnel are joining the search for August Lamont at Yunta in SA’s Mid North Credit: 7NEWS

On Tuesday, SA Police launched Taskforce Horizon — a dedicated team of investigators and search experts tasked with re-examining every angle of the case.

The renewed search effort includes 18 police officers, 82 ADF members, SES volunteers, drones and utility terrain vehicles.

But the clock is ticking. The Bureau of Meteorology has forecast temperatures up to 36°C in the northeast pastoral region, forcing crews to work in the scorching heat to find clues to Gus’s disappearance.

SA Police Commissioner Grant Stevens said the operation remains a recovery mission, not prompted by new evidence of foul play.

“The family are co-operating with the police inquiry … we have nothing to suggest foul play at this time, but we’re obligated to consider every possibility,” he told Adelaide radio station FIVEAA.

“We’re still looking for Gus. That’s really important to the family, to us, and to everybody who’s been involved.”

More than 470 square kilometres have already been searched.

But with no answers and no closure, authorities say they’re not giving up.

“We’ve done everything we can based on expert advice,” Stevens said.

“This is about making sure we leave no stone unturned.”