Terrorist acts occur every day around the world. Healthcare professionals are often present as bystander survivors in these situations, with none of the equipment or infrastructure they rely on in their day-to-day practice. Within several countries there has been a move to disseminate the actions to take in the event of such attacks: in the UK, Run, Hide, Tell, and in the USA, Fight Back. This paper outlines how a very basic medical knowledge combined with everyday high-street items can render highly effective first aid and save lives. We discuss and summarise modern improvised techniques. These include the ABCDE approach of treating catastrophic haemorrhage before airway management, bringing together improvised techniques from the military and wilderness medicine. We explain how improvised tourniquets, wound dressings, splinting and traction devices can be fabricated using items from the high street: nappies, tampons, cling film, duct tape and tablecloths. Cervical spine immobilisation is a labour-intensive protocol that is often practised defensively. With little evidence to support the routine use of triple immobilisation, this should be replaced with a common sense dynamic approach such as the Montana neck brace. Acid or alkali attacks are also examined with simple pragmatic advice. Analgesia is discussed in the context of a prehospital setting. Pharmacy-obtained oral morphine and diclofenac suppositories can be used to treat moderate pain without relying on equipment for intravenous/intraosseous infusion in prolonged hold situations. The differentiation between concealment and cover is summarised: scene safety remains paramount.