If the back seat belts are engaged the vehicle will not be able to be turned off and a chime or verbal prompt will 'remind" the driver to "check the back seat". If after a few minutes the seat belts have not been disengaged the windows will roll down and a loud "child unattended" alarm will sound. If winte,r perhaps the windows stay up and the vehicle mantains a 72 degree inside temperature with windows up but car unlocked.