This AMedP describes the provision of first aid in a CBRN-threat environment by non-medical personnel or medical personnel in a non-permissive environment (hot zone). The main focus for CBRN first aid is the management of a trauma or chemical casualty due to immediate or short-onset effects. However@ enhanced first aid training should also include the recognition and reporting of biological and radiological casualties. Heat illness is a known risk from the use individual protective equipment (IPE) and personnel should be able to recognise and manage heat-related injuries including heat stroke. Psychological casualties may also occur for a number of reasons and may also need to initially be managed at a unit level. Unlike previous CBRN first aid publications@ this guidance is applicable not only to CBRN Defensive Operations but also in response to terrorist / insurgency events as part of the wider Defence against Terrorism (DAT) programme in a civilian or military environment. However@ specific incident management is outside the scope of this document but details on medical CBRN incident management can be found in AMedP-7.1 Part 2: CBRN Medical Incident Management. This AMedP also provides an outline of the training requirement and first aid materiel for use in a CBRN environment including casualty protective equipment (CPE) for the initial response and unit level casualty evacuation (CASEVAC). This is detailed in Annex A.