Emergency Medical Services workers see injury, death, and loss. You interact with shocked and grieving family members while doing your duty. You save many lives and lose some. 
You put in long shifts with crazy schedules; these shifts may be hours of boredom punctuated by intense emergencies or they may be nonstop trauma.
Emergency Medical Services refers to everyone along the pipeline of responding to and treating medical emergencies, accidents, crimes, attacks, and disasters. This includes dispatchers, paramedics, and ER doctors and nurses as well as fire fighters cross-trained as paramedics.