It only takes six minutes for an animal to die from heat stroke, so an animal should never be left in a car, even in the shade or with the windows open.

RSPCA NSW Chief Inspector, David OShannessy said cars left stationary in the sun became ovens.

"Ute trays also become extremely hot, so even those working on building sites with their dogs in the back need to pay particular attention to their animals during the hot weather," Mr OShannessy said.

Every year the RSPCA receives reports of animals suffering heat-related deaths during summer.

Causing animals to suffer in any way is a criminal offence. If a dog suffers as a result of being left in a car, the offender can be fined $5500 and can spend six months in jail. If the dog dies as a result of being left in a car, charges include $22,500 in fines and two years in jail.

Leaving a dog tied up outside the shops in the sun without water can also have dire consequences. If you need to go shopping, leave the dog at home, preferably indoors if the weather is scorching.

If you see an animal showing symptoms of heatstroke - including restlessness, heavy panting, vomiting, lethargy and lack of appetite or co-ordination - move the animal to shade immediately.

Offer water, apply a cold towel to the animal's head and chest or immerse the animal in tepid water.

Call the police if the animal is confined and always call a veterinarian immediately - every second counts.

The RSPCA is asking pet owners to pledge never to leave their dog in a hot car.

To take the pledge visit www.injustsixminutes.com.au