In one week the RSPCA took 28 calls for animals left in hot cars, 62 investigations regarding animals with little or no shade and shelter and 110 reports of animals with insufficient water. You can read more about it at the following Queensland Times article.
What should you do if you see a pet suffering heat stress in/on a vehicle or in a backyard? Call the RSPCA on 1300 ANIMAL (link to call) and contact the Police in cases of emergency.