Basic life support (BLS) is a level of medical care which is used for patients with life-threatening illnesses or injuries until they can be given full medical care by advanced life support providers (paramedics, nurses, physicians).

Cardiac arrest, also known as sudden cardiac arrest (SCA), is a medical condition wherein the heart suddenly and unexpectedly stops beating.

A firefighter is a highly trained individual whose primary role is to extinguish and prevent fires, as well as provide emergency medical services.

Firefighting is a profession aimed at controlling and extinguishing fire.

A fire department (North American English) or fire brigade (Commonwealth English), also known as a fire company, fire authority, fire district, fire and rescue, or fire service in some areas, is an organization that provides fire prevention and fire suppression services as well as other rescue services.

First aid is the immediate and temporary care provided to an injured or ill person until professional medical assistance arrives.

Greater London is a ceremonial county and region of England that constitutes the southern part of the country's capital city, London.

London is the capital city of England and the United Kingdom, located on the banks of the River Thames.