Introduction The Carmel fire resulted in the death of 45 rescue workers. Little research exists on the health risks to emergency responders during forest fires and the immediate and long term psychological impact from occupational stressors. There is no prospective cohort studying the long term mental health effects among first responders.

Methods A retrospective exposure assessment was performed on 300 first responders, assessing personalised exposure to occupational stressors such as severe lack of sleep, fear for personal safety, and witnessing death of other rescue workers. Frequency of psychological symptoms and mental health diagnoses were assessed among the cohort prospectively over a three year period. Unpaired two sample t-test compared mean exposures and symptom frequency for firefighters and police separately and together. Chi-square estimates of Odds Ratio and 95% CI are provided for odds mental health outcomes

Results Occupational stress was extremely high; the average length of time working without rest was 18.4 hours. 57% responded that their personal safety was severely at risk, and 49% felt at severe risk of losing their life. 24% (17% of firefighters and 44% of police) reported at least one acute stress related symptom following the fire, while 10% (6% of firefighters and 21% of police) continue to have PTSD 1 year following the fire. A strong inverse correlation between level of training, years of experience, and availability appropriate protective equipment, baseline health status exists with psychological outcomes. There was a strong positive correlation between availability of occupational health services, proximity to fire, risk perception with psychological outcomes.

Conclusion First responders were exposed to significant occupational stressors during the Carmel fire. These exposures and organisational factors increased the odds of acute stress disorder and PTSD. Further research is needed on the residual mental health effects among emergency responders from occupational stressors, and efficacy of preventative policies.