Pay attention, I've already made it clear in this thread that I have at least two.
Still waiting for someone to point out the risk of leaving children in a locked car in a public car park.
There are risks Vonhelmet and as a responsible Parent you are fully aware of them.
Much of whether it is safe to leave a child depends foremost on three things, their Age, the situation, and their innate level of personal responsibility.
While it is perfectly acceptable to leave your 6 year old in the car for a few minutes while paying for petrol, it would not be advisable to do so and then go into Tesco to do a two hour shop.
In the case of an 18 month old baby, we have several obvious risks. One is abduction, rare but it does happen. The other is the same with any baby and that is if there is a problem you have no way of knowing (unless you are carrying around a baby monitor) and if the child chokes, falls ill or simply becomes irritated and crying you would have no way to know.
Again, the weather is also a risk, especially hot weather. Car theft another.
There is the risk to you, what happens if you are taken ill and cannot tell anyone that there is a child in your car, how long would it take for someone to know?
There is also the risk that someone will report the incident to the authorities, now leaving a child only becomes an offence if it is deemed that in doing so constitutes an unnecessary risk to the child, but it is obvious that the authorities will take a pretty dim view of anyone leaving an 18 month old Baby unattended anywhere, even in a locked vehicle.
Many of these risks are comparable to leaving a baby in a bedroom alone, which we all do, however in your home there are systems that any parent has of checking their child, especially a baby, be it monitors, looking in on them from time to time and so on. Also if something were to happen, you are on hand immediately to do something about it, and if something where to happen to you then whatever authority responded would have a clear picture that a child is in the house.
So basically this is one of those debates that depends on what the individual deems as acceptable based on their children and as such is open to opinion.
For me there are several things we need to consider if we are to decide whether leaving a child is acceptable or not:
The age of the child, are they 18 months or 6 years or 16 years.
The child's level of maturity and understanding, could they deal with a simple emergency if it were to happen.
The place where the child will be left, is the place safe and as free from risks as is practicable, can you see any obvious risk yourself.
How long, and how often, the child will be left alone, it may be fine to leave a 14 year old alone for an evening, but would it be ok for a week?
In the case of the 18month old being left in the Car with no sign of the Parents, I would say that was irresponsible, the child is too young, there appears to be no way that the Parents could respond to an emergency and the Child is too young to raise an alarm or have any sense of maturity in regard their own safety.