The RSPCA stated that during the five-day heatwave in the UK recently, 724 dog owners left their dogs alone in the car and they had to be rescued.
In Kent, I found two dogs in a car during a heatwave, two retrievers, the owner had disappeared to a coffee shop. One of the dogs was in a bad state. I called the RSPCA, but they were eventually rescued by the local PSCO.
The RSPCA said that one dog was rescued after one and an half hours, according to the parking ticket in a shopping centre car park so passers by ignored the suffering dog for a long time. In my own experience, there were several passers by but nothing was done, they did not notice or seemed interested, it takes a dog lover to notice suffering dogs in a car. Supermarkets have trolley marshalls who should have noticed dogs earlier, why does it take one an half hours for a dog to be rescued?
In parts of the US, they have now passed a new law that if members of the public sees an animal in distress in a car, they can smash the window open. Unfortunately, in the UK, members of the public cannot do this.
Contact your local RSPCA https://www.rspca.org.uk/utilities/contactus