The three men who pulled the toddlers from the burning vehicle before resuscitating them and treating their burns have been hailed as heroes.
The children were flown to Waikato Hospital's intensive care unit from Gisborne Hospital overnight, a hospital spokeswoman said.
Witnesses say the children, a 22-month-old boy and his 3-year-old sister, had been left alone in the vehicle about 4.30pm yesterday in a carpark outside Super Cheap Autos on Gladstone Rd.
A staff member at Supercheap Auto in Gisborne saw smoke pouring from the car and made a call over the public address system.
"A woman came running out and it was only then we realised there were children in there," said the worker. "She was totally hysterical and traumatised."
There was a small explosion and flash fire which produced clouds of black smoke, witnesses said.
John Spawforth, who works at The Mill beside Supercheap Auto, said the three men who rescued the children were "absolute heroes".
"They were the ones who sprinted across the road, put the fire out and dragged these kids out ... I ran out with two things of water to pour over the children.
"It was horrific. Their skin was hanging off them," Mr Spawforth said. "The mother was just standing in the carpark bawling her eyes out."
They suffered burns to 40 per cent of their bodies.
Several bystanders rushed to the children's aid straight after the explosion.
Mutu Ngarimu, who runs a business alongside the carpark, said he saw smoke coming from the vehicle. He grabbed a fire extinguisher from under his desk and ran to help.
Two men working across the road at the Firestone tyre store also saw the smoke and ran across the road.
They and Mr Ngarimu climbed into the back of the vehicle and pulled out the unconscious children.
Mr Mutu revived the boy while another man resuscitated the three-year-old girl.
The two youngsters suffered "serious burns", Fire Service central communications shift manager Belinda Beets said.
"They were heroes, those guys," said one witness.
St John paramedic Jackie Clapperton said staff from nearby businesses did a good job getting the children out, reviving them and treating their burns.
St John district operations manager Stephen Smith praised the work of the witnesses who rescued the children, and said they may have made the difference in saving the children's lives.
"From our point of view, removing the children from the fire and providing that initial first aid has contributed greatly to their care."
"I just hope the kids pull through," Mr Ngarimu told the Gisborne Herald.
Fire safety officials and police are investigating the cause of the blaze.
- Amelia Wade
