Charles has worked in emergency and critical care since 1980 in various capacities. He has worked in ICU, ER, Telemetry, Respiratory Therapy, Interventional Radiology, and IV Therapy, as well as Diabetes Education. He is currently an instructor for Instruction By Masters in Electrocardiograph rhythm recognition, Basic Life Support, Heartsaver CPR, First-Aid, Advanced Cardiac Life Support, and Pediatric Advanced Life Support.