An incident response team (IRT) or emergency response team (ERT) is a group of people who prepare for and respond to an emergency, such as a natural disaster or an interruption of business operations. Incident response teams are common in public service organizations as well as in other organizations, either military or specialty. This team is generally composed of specific members designated before an incident occurs, although under certain circumstances the team may be an ad hoc group of willing volunteers. Incident response team members ideally are trained and prepared to fulfill the roles required by the specific situation (for example, to serve as incident commander in the event of a large-scale public emergency). As the size of an incident grows, and as more resources are drawn into the event, the command of the situation may shift through several phases. In a small-scale event, usually only a volunteer or ad hoc team may respond. In events, both large and small, both specific member and ad hoc teams may work jointly in a unified command system. Individual team members can be trained in various aspects of the response, either be it medical assistance/first aid, hazardous material spills, hostage situations, information systems attacks or disaster relief. Ideally the team has already defined a protocol or set of actions to perform to mitigate the negative effects of the incident. Examples of incidents Incident response teams address two different types of incidents. The first of these types is public. This covers larger incidents that affect a community as a whole, such as, natural disasters (hurricane, tornado, earthquake, etc.), terrorism, large-scale chemical spills, and epidemics. The other type is organizational: this would be an incident that happens on a smaller scale and affects mostly just single company or organization. Examples of organizational incidents can include: bomb threats, computer incidents such as theft or accidental exposure of sensitive data, exposure of intellectual property or trade secrets, and product contamination. Incident response teams Predefined roles are typically filled with individuals who are formally trained and on standby at all times, during scheduled hours. These teams are organized by ranks with a clearly defined chain of command. Examples include: Imperial College COVID-19 Response Team: A crisis-time scientific and advisory team set up by Imperial College London within the Faculty of Medicine to study the COVID-19 pandemic and advise the government of the United Kingdom. Special Weapons and Tactics