A critical incident is any event or series of events that is sudden, overwhelming, threatening or protracted. This may be an assault, threats, severe injury, death, fire or a bomb threat. Critical incident stress management aims to help workers deal with emotional reactions that may result from involvement in or exposure to unusual workplace incidents.

A critical incident can be overwhelming and threatening and may lead to distress. This can be harmful when a person has demands and expectations that are out of keeping with their needs, abilities, skills and coping strategies. Distress can result in a decline in performance and in overall levels of wellbeing.

Involvement in, or exposure to, abnormal workplace incidents can lead a person to experience distress. It is normal to react emotionally to a critical incident. This may involve recurrent thoughts about the event, feeling uneasy or anxious, mood changes, restlessness, feeling tired and disturbed sleep.

Critical incident stress management provides support to assist the recovery of normal individuals experiencing normal distress following exposure to abnormal events. It is based on a series of comprehensive and confidential strategies that aim to minimise any adverse emotional reaction the person may have.

Critical incidents may trigger a wide range of physical and psychological symptoms, including increased heart rate, high blood pressure and anxiety. Demobilisation (rest, information and time out) is a way of calming workers following a critical incident and ensuring that their immediate needs are met. A supervisor or manager who was not involved in the incident, or affected by it, carries out the demobilisation.

Defusing (immediate small group support) is usually conducted by a trained staff member and is designed to bring the experience of the incident to a conclusion and provide immediate personal support. The aim is to stabilise the responses of workers involved in the incident and provide an opportunity for them to express any immediate concerns.

Debriefing (powerful event group support) is usually carried out within three to seven days of the critical incident, when workers have had enough time to take in the experience. Debriefing is not counselling. It is a structured voluntary discussion aimed at putting an abnormal event into perspective. It offers workers clarity about the critical incident they have experienced and assists them to establish a process for recovery.