Tesla cars include a feature that stops the interior exceeding a certain temperature, and the company's CEO Elon Musk says that a future update may include a 'Dog Mode', which would display a message warning passers-by not to panic if they see a pet inside a parked vehicle.
When a Tesla owner suggested the concept via Twitter, Musk confirmed that it could indeed be implemented, with a sign on the rear window letting the public known the dog's owner would be back very soon. He also agreed that such a mode could include a display of the current interior temperature so well-meaning strangers don't break the car's window to rescue your pup.
The temperature-regulating feature, called Cabin Overheat, was pushed out to Tesla vehicles via a software update in June. When the car is parked, Cabin Overheat ensures that the temperature inside the car doesn't exceed a preset limit (a rather toasty 40C by default).
However, despite Musk's positive response, this is meant for safety rather than convenience - so your animal will be safe if you accidentally leave it in the back seat for a few minutes, not for keeping them comfortable over long periods.
The American Society for the Prevention of Cruelty to Animals (ASPCA) advises never leaving a dog alone in a parked car, and notes that doing so is illegal in several states.