When someone has successfully completed a Standard First Aid Course, they often have a desire to extend their knowledge of first aid. The aim of this book is to give the holders of a Standard First Aid Certificate the opportunity to study the principles of first aid in greater detail. It is not intended to convert the first aider into a highly trained paramedic - so a discussion on the use of intra venous fluids, defibrillators etc., is beyond the scope of this book. It is hoped that the book will provide a useful in-depth study for demonstrators, instructors and first aiders likely to be involved in ambulance duties. I am very grateful to Brigadier D.O. O'Brien, Chief Medical Adviser, British Red Cross Society and Mrs. R.H. Smith, Assistant Branch Director (Training), Leicestershire Branch of the British Red Cross Society for their helpful comments and encouragement. I acknowledge the use of illustrations from the Clinical Symposia Series by CIBA on the "Heimlich Manoeuvre" to form the basis of Figures 3.7,3.8 and 3.9.