It has been observed that due to central locking of the door or due to the mistake of the concerned person (parent), when they leave their child in the car, that kid is unable to open the door when it is locked.

So if we introduce an oxygen sensor which senses the oxygen level which is connected to a PLC where there is set a minimum level if oxygen to be there for breathing, and when this happens will signal an alarm or will signal the window sliding mechanism to slide down by a given distance and again close or it can do both -- turn on the alarm and perform the function of sliding the window up and down.

The window can be kept open but it is possible the car could be stolen. So it is advisable to close the window after a specified time.