In Case Of Emergency

Use all your senses to obtain maximum information and diagnose the casualty – look, speak, listen, feel and smell.
If the casualty is conscious:

look and size up the problem as you approach;
ask him if he has pain and where it is;
examine that part first;
ask him if he thinks there is anything else wrong;
examine the casualty carefully [...]

The First Aider must first reduce to a minimum any danger to the casualty or to himself (take care to avoid becoming a second casualty), e.g. in the case of:

fire and collapsing buildings: move the casualty to
safety;
road accidents: instruct someone to control the [...]