The MHMI series is a three volume set of pdfs (with a video) comprised of recommendations for on-scene (prehospital), and hospital medical management of patients exposed during a hazardous materials incident. Vol I: Emergency Medical Services; Vol II: Hospital Emergency Departments; Vol III: Medical Management Guidelines.The MHMI series is a three volume set of pdfs (with a video) comprised of recommendations for on-scene (prehospital), and hospital medical management of patients exposed during a hazardous materials incident.