An animal protection officer with the P.E.I. Humane Society rescued seven dogs from a parked van in Charlottetown this week.
Jeff Barrett told CBC News Wednesday even though the owner had left the side door of the van open, the temperature inside the vehicle where the dogs were kept in kennels was probably in the low 40s.
"It really happens surprisingly fast," said Barrett.
"With the windows cracked a couple of inches down the temperature can still rise as much as 10 or 15 degrees in 10 minutes inside a hot car. So if it's 25 degrees outside it very quickly becomes 35 or 40 inside the car, even in five or 10 minutes. So it's very dangerous, even if you're just running into the store."
Barrett said the dogs were checked out by a veterinarian and once they were deemed to be fine they were returned to their owner on the condition the person not keep them in the vehicle on hot days again.
No charges were laid because none of the dogs were harmed.