The invention is a system for providing decision-assisted critical care to a patient in medical emergency situations in an out of hospital setting. The system comprises: a ventilator comprising a pressure generator and oxygen/air delivery means; an Automated External Defibrillator (AED) comprising a battery and primary electrocardiogram (ECG) sensors configured as chest pads that are configured to be connected to the chest of the patient and to both sense ECG and to deliver an electric shock to the patient's heart; at least one secondary ECG sensor configured to sense ECG but not to deliver electric shock and to be connected to the body of the patient at a location other than the chest; and a controller, configured to activate or instruct a caregiver to activate, the AED and to place the chest pads on the chest of the patient upon detection of shockable cardiac arrhythmias by at least one of the at least one secondary ECG sensors.