The SPCA says some dog owners are still under-estimating the risk of leaving their pets in vehicles on warm days.
In the past year, the charity has received 214 complaints about dogs being left in hot cars.
SPCA inspector Ben Lakomy said it was disappointing the message still was not getting through to some people.
"It is an offence under the Animal Welfare (Care and Procedures) Regulations 2018, to leave a dog in a hot vehicle if they are showing signs of heat stress, such as excessive panting, drooling or hyperventilation, and trying to seek shade.
"When it's 21C outside, temperatures in a car parked in the shade with the windows down can exceed 31C in less than 10 minutes. In 30 minutes, it goes up to 40C. On a hot day, the temperature inside the vehicle can exceed 50C."
Pet owners, whose dogs were found in this state, could be issued with a $300 infringement notice.
Lakomy said SPCA inspectors across the country have noticed a number of people in emergency housing where dogs were residing long-term in vehicles.
Some action educating dog owners had taken place over winter but it could be a bigger worry in the warmer months.
SPCA chief executive Gabby Clezy also encouraged dog owners to think again before leaving their dog in the car on hot days.
She said people sometimes thought they were would be just a few minutes away from their car but could get distracted and it would turn into a much longer time.
"If you're planning on going out for a short time, leave your dog at home, or in the care of a friend, family member or neighbour. We know dogs are such important companions, but it's important to put their welfare first."
Lakomy said people could contact the SPCA or the police if they were concerned about dogs in a car.
RNZ
