A bus driver has been suspended after a two-year-old boy was left unattended in the vehicle outside a New South Wales childcare centre for six hours yesterday.

Key points: The toddler was taken to Yass District Hospital as a precaution

The toddler was taken to Yass District Hospital as a precaution The incident was reported to Family and Community Services

The incident was reported to Family and Community Services The bus driver has been suspended

Yass Little Learners Centre staff confirmed that the toddler, a boy named Alijah, was alone on the bus for multiple hours and the female driver had been suspended, pending an investigation.

The temperature in the southern NSW town reached 26 degrees Celsius by the time the boy was found inside the parked vehicle on Wednesday afternoon.

He had allegedly been left unattended since 9:00am.

The boy was treated for dehydration and taken to Yass District Hospital as a precaution.

Alijah was later discharged into the care of his mother Cassandra Brown-Crane, who said he bounced back quickly.

Cassandra Brown-Crane (right) with son Alijah and a worker at the childcare centre Yass Little Learners. ( Supplied )

"Accidents do happen and sadly this could have been tragic but it wasn't, my son's happy and healthy," she said.

"I'm very relieved that it didn't end up fatal.

"I will remember this day forever and I'm so thankful that he is healthy and alive.

Yass Little Learners director Steve Grundy said the centre had used a bus to operate a daily school run service since early 2017.

He said the family-run operation had "very stringent check protocols" but he said he could not go into details because of the police investigation.

Mr Grundy said Alijah only attended the early learning centre a few days a week, so staff did not notice his absence.

He would not specify how he was left in the bus or how he was found.

Steve Grundy says Alijah is now doing well, running around with an icy pole. ( ABC News: Alexandra Alvaro )

Ms Brown-Crane said she did not blame the childcare centre for what happened.

"My son is doing ok, he's in the care of Yass Little Learners today. I love this centre, it's a family here," she said.

"There's no slander made about it because this place is more of a family than some would have."

Child back at centre day after incident

Mr Grundy said Alijah was at the centre today, along with his mother and expressed immense relief that the toddler was "safe and well".

"The little fella is running around here today eating an icy pole," he said.

But he said staff at the centre, including the bus driver, were "traumatised" by what had happened.

"Things like this are horrible and we just need to make sure that we check and double-check everything to make sure that something like this doesn't happen again," he said.

"We're shocked and traumatised over this incident and we're very much making sure that the mother and child are very well, which indeed they are — they're here in the centre right now.

"But I need to make sure that [the bus driver] is looked after as well."

Mr Grundy said other parents at the centre were "very upset" but "very supportive".

"To the general population of Yass, we're so upset about this and we'll be working to improve what we're doing and to make sure that something like this never reoccurs," he said.

Mr Grundy said centre staff reported the incident to the Department of Family and Community Services (FACS).

A spokeswoman from FACS said staff were "deeply concerned" to hear about the incident.

But she said, as a police investigation was underway, the department was unable to comment further.

A senior staff member at the centre will take over driving duties in the interim while the business advertises for a new bus driver.