First responders at the Federal, State and local level are those on the front lines of providing support to their communities during an emergency or a disaster. Their work domains are emergency public security, firefighting, law enforcement, emergency response, and emergency medical care. Due to the inherent characteristics of the jobs they perform, they are constantly exposed to very stressful, demanding and dangerous work environments. Such an exposure often leads to mental health issues such as anxiety, depression, and post-traumatic stress disorder (PTSD). More than 80 percent of first responders experience traumatic events on their job duty. Various efforts to treat about trauma have been made to address the first responders' mental health. However, existing interventions are not directly targeted at the causes of mental health problems, which is the memory of the adverse events. The objective the proposed research is to investigate the effect of immersive virtual reality (VR) experience on the memory of an adverse event (e.g., fire).