To illustrate, imagine that someone collapses in sudden cardiac death and a bystander calls 911. An EMT arrives first on a fire engine. The EMT would begin CPR, administer rescue breaths using a bag-valve-mask and oxygen, attach an automatic external defibrillator (AED), and shock or defibrillate the patient if so instructed by the AED.
Then a paramedic on an ambulance arrives. The paramedic would attach a manual heart monitor/defibrillator, interpret the electrocardiogram (ECG), and defibrillate if needed. The paramedic would insert a breathing tube in the patient’s trachea, start an IV, and give potent medicines such as epinephrine through the IV.
Broadly speaking, EMTs have basic training and provide emergency care in a non-invasive manner. Paramedics undergo more advanced training that includes invasive treatments and medication administration.
Within the Cosumnes Fire Department, all ambulances and first-responders (fire engines and fire trucks) are staffed by at least one paramedic. Other personnel on these units are trained at least to an EMT level.