Don't rush to help the victim until you are certain that he is no longer in contact with electricity.
Turn off the source of electricity (if possible).
Begin CPR if the person shows no breathing or movement.
Try to precent the injured person from becoming chilled.
Apply a bandage, don't cover any burns with a blanket or towel because loose fibres could stick to the burn.
Call 999 emergency services.
Watch over patient until emergency services come.