To prevent this from happening, it is important to turn off the blower motor before turning off the vehicle. This can be done by either using the climate control panel or by turning the ignition key to the "off" position.
If the blower motor does accidentally get left on, it is important to turn it off as soon as possible to prevent the battery from draining. This can be done by either using the climate control panel or by turning the ignition key to the "on" position and then back to the "off" position.