Glossary

Name Acronym Description
Heat flux

Heat flux refers to the quantity of heat as thermal radiation, and measured in kW/m2, that is received at a particular point

Heavy goods vehicle

A commercial goods vehicle designed or adapted to have a maximum weight exceeding 3500kg

Helical flow

A spiralling effect caused by the bank slowing the water at the edge of the river and the faster movement of mid-channel water. Helical flow pushes a person away from the bank and into the centre of the flow.

Hot spots

Hot spots, sometimes called bullseyes, are areas of intense heat in a fire. They may have the potential to reignite.

Hydraulic injection

Hydraulic injection injury occurs when the outer layer of skin is broken by a jet of fluid under pressure

Hyperthermia

Hyperthermia is an abnormally high body temperature (included in the operational guidance under heat illness)

Hypothermia

Hypothermia is a dangerous drop in body temperature below 35°C, with normal body temperature being around 37°C for humans

Immediate care practitioners

Registered medical practitioners, nurses and paramedics

Immersion

The act of putting something or someone completely under the surface of a liquid

Immiscible

An immiscible liquid or material cannot be mixed with another liquid or material without separating from it

Improvised decontamination

The use of an immediately available method of decontaminating members of the public before using specialist resources

Improvised explosive device IED

An IED is a bomb which can be made from Homemade Explosives (HME). Although IEDs may be ‘home made’, they can still be as powerful as commercial or military explosives, be sophisticated in their design and be very effective.

Infrastructure manager

An infrastructure manager is the person who is responsible for developing, maintaining, managing or operating an infrastructure

Initial operational response IOR

IOR is focused on the activities that the public can immediately do for themselves and actions the emergency services need to undertake during the initial reporting stage and at the scene of an incident involving hazardous substances prior to the arrival of Specialist Operational Response (SOR) assets

Interim decontamination

The use of standard equipment to provide a structured decontamination process before purpose-designed decontamination equipment is available

International ship-to-shore connection

An international shore connection to be used with marine firefighting systems during an emergency when a stricken vessel has a system failure. International shore connections are portable universal couplings that permit connection of shipboard fire main systems between one vessel and another or between a shore facility and a vessel when their respective system threading is mismatched. Both the vessel and the facility are expected to have a fitting such that in an emergency can be attached to their respective fire hose and bolted together to permit charging the vessel’s system.

Interoperability

The extent to which organisations can work together coherently as a matter of routine, often referred to as a multi-agency response

Intraoperability

The extent to which fire and rescue services can work together coherently as a matter of routine, often referred to as cross-border response

Intrinsically safe

A term widely used for equipment and tools that are considered safe to use in explosive atmospheres

Invacuation

Process of confining people to a space in an emergency, especially on board a vessel

Inverter An inverter (or power inverter) is an electronic device or circuitry that changes direct current (DC) to alternating current (AC) or vice versa
Ionisation

Process by which electrons can be added or removed from an atom to create an ion

Ionising radiation

A type of energy released by atoms that travels in the form of electromagnetic waves (gamma or X-rays) or particles (neutrons, beta or alpha). The spontaneous disintegration of atoms is called radioactivity, and the excess energy emitted is a form of ionising radiation.

Irradiation

Irradiation is either defined as exposure to radiation (such as X-rays or alpha particles) or the application of radiation (such as X-rays or gamma rays) for therapeutic purposes or for sterilisation of food

Ladder fuel

Vegetation, including shrubs and small trees, that is located below the crown level of forest trees, which can spread fire from the forest floor to tree crowns

1 2 4 5 6 10 11