An emergency is a situation which poses an immediate risk to health, life, property or environment. Most emergencies require urgent intervention to prevent a worsening of the situation, although in some situations, mitigation may not be possible and agencies may only be able to offer palliative care for the aftermath.
Whilst some emergencies are self evident (such as a natural disaster which threatens many lives), many smaller incidents require the subjective opinion of an observer (or affected party) in order to decide whether it qualifies as an emergency.
The precise definition of an emergency, the agencies involved and the procedures used, vary by jurisdiction, and this is usually set by the government, whose agencies (emergency services) are responsible for emergency planning and management.
Whilst most emergency services agree on protecting human health, life and property, the environmental impacts are not considered sufficiently important by some agencies. This also extends to areas such as animal welfare, where some emergency organisations cover this element through the 'property' definition, where animals which are owned by a person are threatened (although this does not cover wild animals). This means that some agencies will not mount an 'emergency' response where it endangers wild animals or environment, although others will respond to such incidents (such as oil spills at sea which pose a threat to marine life). The attitude of the agencies involved is likely to reflect the predominant opinion of the government of the area.
Most agencies consider these to be the highest priority of emergency, which follows the general school of thought that nothing is more important than human life.
The causes of a 'health' emergency are often very similar to the causes of an emergency threatening to life, which includes medical emergencies and natural disasters, although the range of incidents which can be categorised here is far greater than those which cause a danger to life (such as broken limbs, which do not usually cause death, but immediate intervention is required if the person is to recover properly)
Many agencies categorise property emergency as the lowest priority, and may not take as many risks in dealing with it. For instance, firefighters are unlikely to enter a burning building which they know to be empty, as the risk is unjustified, whereas they are more likely to enter a building where people are reported as trapped.
The first stage in any classification is likely to be defining whether the incident qualifies as an emergency, and consequently if it warrants an emergency response. Some agencies may still respond to non-emergency calls, depending on their remit and availability of resource. An example of this would be a fire department responding to help retrieve a cat from a tree, where no life, health or property is immediately at risk.
Following this, many agencies assign a sub-classification to the emergency, prioritising incidents which have the most potential for risk to life, health or property (in that order). For instance, many ambulance services use a system called the Advanced Medical Priority Dispatch System (AMPDS) or a similar solution. The AMPDS categorises all calls to the ambulance service using it as either 'A' category (immediately life threatening), 'B' Category (immediately health threatening) or 'C' category (non-emergency call which still requires a response). Some services will now also have a fourth category, where they believe that no response is required after clinical questions are asked.
Another system for prioritizing medical calls is known as Emergency Medical Dispatch (EMD). Jurisdictions that use EMD typically assign a code of "alpha" (low priority), "bravo" (medium priority), "charlie" (requiring advanced life support), delta (high priority, requiring advanced life support) or "echo" (maximum possible priority, e.g., witnessed cardiac arrests) to each inbound request for service; these codes are then used to determine the appropriate level of response.
Other systems (especially as regards major incidents) use objective measures to direct resource. Two such systems are CHALET and ETHANE, which are both mnemonics to help emergency services staff classify incidents, and direct resource. Each of these acronyms helps ascertain the number of casualties (usually including the number of dead and number of non-injured people involved), how the incident has occurred, and what emergency services are required.
Most developed countries have a number of emergency services operating within them, whose purpose is to provide assistance in dealing with any emergency which may occur. They are often government operated, paid for from tax revenue as a public service, but in some cases, they may be private companies, responding to emergencies in return for payment, or they may be voluntary organisations, providing the assistance from funds raised from donations.
Most developed countries operate three core emergency services which are:
In some countries or regions, two or more of these services may be provided by the same agency (e.g. the fire service providing emergency medical cover), and under different conditions (e.g. publicly funded fire service and police, but a private ambulance service)
There may also be a number of secondary emergency services, which may be a part of one of the core agencies, or may be separate entities who assist the main agencies. This can include services providing specialist rescue (such as mountain rescue or mine rescue), bomb disposal or search and rescue.
The Military and the Amateur Radio Emergency Service (ARES) help in large emergencies such as a disaster or major civil unrest.
The majority of mobile phones will also dial the emergency services, even if the phone keyboard is locked, or if the phone has an expired or missing SIM card, although the provision of this service varies by country and network.
In addition to those services provided specifically for emergencies, there may be a number of agencies who provide an emergency service as an incidental part of their normal 'day job' provision. This can include public utility workers, such as in provision of electricity or gas, who may be required to respond quickly, as both utilities have a large potential to cause danger to life, health and property if there is an infrastructure failure.
Emergency action principles are the key 'rules' which guide the actions of rescuers and potential rescuers. Because of the inherent nature of emergencies, no two are likely to be the same, so emergency action principles help to guide rescuers at incidents, by sticking to some basic tenets.
The adherence to (and contents of) the principles by would be rescuers varies widely based on the training the people involved in emergency have received, the support available from emergency services (and the time it will take to arrive) and the emergency itself.
The reason that an assessment for danger is given such high priority is that it is core to emergency management that rescuers do not become secondary victims of any incident, as this creates a further emergency that must be dealt with.
A typical assessment for danger would involve observation of the surroundings, starting with the cause of the accident (e.g. a falling object) and expanding outwards to include any situational hazards (e.g. fast moving traffic) and history or secondary information given by witnesses, bystanders or the emergency services (e.g. an attacker still waiting nearby).
Once a primary danger assessment has been complete, this should not end the system of checking for danger, but should inform all other parts of the process.
If at any time the risk from any hazard poses a significant danger (as a factor of likelihood and seriousness) to the rescuer, they should consider whether they should approach the scene (or leave the scene if appropriate).
There are many protocols which the emergency services use in dealing with an emergency, which usually start with planning before an emergency occurs. One commonly used system for demonstrating the phases is shown here on the right.
The planning phase starts at preparedness, where the agencies decide on how they will respond to a given incident or set of circumstances. This should ideally include lines of command and control, and division of activities between agencies. This avoids potentially negative situations such as three separate agencies all starting an official rest centre for victims of a disaster.
Following an emergency occurring, the agencies then move to a response phase, where they execute their plans, and may end up improvising some areas of their response (due to gaps in the planning phase, which are inevitable due to the individual nature of most incidents).
Agencies may then be involved in recovery following the incident, where they assist in the clear up from the incident, or help the people involved overcome their mental trauma.
The final phase in the circle is mitigation which involves taking steps to ensure that no re-occurrence is possible, or putting additional plans in place to ensure less damage is done. This should feed back in to the preparedness stage, with updated plans in place to deal with future emergencies, thus completing the circle.
In the event of a major incident, such as civil unrest or a major disaster, many governments maintain the right to declare a state of emergency, which gives them extensive powers over the daily lives of their citizens, and may include temporary curtailment on certain civil rights, including the right to trial (for instance to discourage looting of an evacuated area, a shoot on sight policy may be in force)
Some of these cases may be genuine emergencies if they threaten the mental health and well-being of the person involved, but many agencies do not recognise this as valid. This is more likely to be dealt with by social services or a physician than by the traditional emergency service agencies.