I've read that it's not okay to ever leave your dog/puppy alone in your car. I plan to get a new puppy (probably a miniature poodle or a pug). I go to a gym every day and am in and out within one to two hours. I was thinking how much more convenient it would be to leave my puppy/dog in the car, locked with the air conditioner on (in hot weather) and the heater on (in cold weather). That way I wouldn't have to go all the way back to my house (I'm retired and live alone) to pick up my dog to go somewhere like a park, dog store, etc. I live in a good area. I suppose I need to ask car experts if it's okay to leave the car in idle for up to two hours on a daily basis. Only rarely have I ever seen a dog locked in a car (supermarket parking lot), but the car wasn't idling.