As temperatures are rising in the build up to summer an, NSW Ambulance said on Wednesday the consequences of locking children in cars for even a few minutes can be “catastrophic”.

Paramedics have been called to 81 children trapped in vehicles across the state, an average of about one child a day since September 1.

NSW Ambulance Chief Inspector Brian Parsell said in a statement temperatures inside vehicles can soar to well over 50 degrees.

“I recorded the temperature inside a car for some internal research last summer and it reached 78 degrees in just minutes,” he said.

“Babies and small children are unable to regulate their body temperature as efficiently as adults.

“They absorb more heat from the environment than they can dissipate.

“This situation can quickly cause damage to body cells leading to unconsciousness, shock, organ failure and death.

“Even in milder temperatures, children and babies can get sick very quickly.”

Chief Inspector Parsell said in some cases children had been locked in cars accidentally and urged parents to be extra vigilant.

“Be mindful of vehicle security systems, in particular the location of keyless fobs which can lock cars if left inside the vehicle,” he said.

Chief Inspector Parsell was on scene at Glenwood on Christmas Eve last year when a three-year-old girl died after being left in a vehicle.

“It only takes a few minutes and the consequences can be catastrophic,” he said.

He said no matter how quick a person thinks they are going to be, they should never intentionally leave a child – or pets - unattended in a car.

“The effort it takes to bring your child with you is nothing compared to the trauma of your child being left in an overheated vehicle.”

If people find a distressed child locked in a car dial Triple Zero (000) immediately and ask for Ambulance.

They should stay on the line until paramedics arrive.