I worked ER as a tech while in Nursing school then had to put in a year on the floor before they would hire me as a nurse. I felt like I lost knowledge and skills while on the floor for that year. you have to know about all ages and all diseases while in ER. You have to be compassionate while knowing how not to be manipulated by drug seekers. If you like it, it "gets in your blood". There are multiple certifications you need after getting your license that help you in the ER such as Advanced Cardiac Life Support, Trauma Nursing Core Course, Pediatric Advanced Life Support, and many more. Those are nursing ones (b/c I am a nurse) I'd suggest looking on some hospital web sites of what they are wanting for their employees and that will tell you more Good Luck