The mental health of first responders relies on a victim-based framework expressed in psychiatric terms describing mental disorders. Expert guidelines that recommend four weeks of ‘watchful waiting’ of post-traumatic stress reactions contradict the emergency services’ ethos of rapid response in workers who encounter stressors, not as victims, but as cooperative teams attracted to the work. An occupational health and safety perspective that addresses pre-incident, operational and post-incident factors should see a dynamic picture emerge that is theoretically informed, legally compliant and realistic. The two examples of first responders in the voluntary and professional emergency services in South Australia, and the peer-support response to the terrorist attacks and Grenfell Tower fire in London are considered. An approach that reinterprets symptoms as reactions can turn the four-week waiting period into a time of fruitful crisis intervention that may prevent mental disorder and assure first responders of their mental health and well-being.