Good Samaritan Law was passed for providing the first aider giving first aid to anyone who is ill or injured, or in distress. It gives protection to each First aider if he is giving first aid voluntarily without any greed for reimbursement or compensation. Remember to call Emergency team before starting CPR as every second counts.
Safety of first aider is the Golden Rule that should always be followed before starting any first aid procedure.
If there is a life-threatening situation, immediately move the patient to the nearby safe zone. Do not forget to call 112 or emergency response team.
Never look out for pulse initially to check for well being as it may take too much time. Gently tap on the shoulder and ask the injured "Are you Okay?" If there is no response from the casualty, "Call 112" and start the CPR immediately.
If you are all alone and no one near you than CALL 112 and after that start CPR to minimize damage.
If someone is present, beside you he will call 112 and you can administer CPR without any delay.