If someone is unconscious, follow the DR ABC code
Danger - Check for danger
Response - Ask the casualty questions and gently shake the shoulders for a response
Airway - Check the airway is clear
Breathing - Check for breathing for up to 10 seconds
Compressions - Using two hands in the centre of the chest, press down 5 - 6cm at a rate of 100 per minute. Use one hand, gently for a small child (two fingers for an infant)