Injury in electrical work is usually caused by direct contact with a live conductor and may consist of either a shock, burns, or both.

When the electric current enters the body, it causes more or less complete paralysis of the nervous system; this in turn causes the heart and lungs to cease functioning. The degree of the shock depends upon certain conditions. For example, if an electric circuit is completed by making a contact with the body at the shoulder and hand of the same arm, the current will pass through the arm and not reach the heart and lungs. On the other hand, if the circuit is completed from hand to hand the current will pass through the body near the heart and lungs and may be sufficient to cause death. Sometimes the shock may not kill but stun the person to such a point as to stop his breathing. This is due to the fact that the skin of the body, unless wet, offers high resistance to the current and the conductor makes only a short and incomplete contact with the body. A person can be released from a contact with a live conductor only by means of a piece of dry, non-conducting material, such as a piece of wood, a coat, rope, or hose. If possible, the switch should be turned off or the wire should be cut by means of rubber protected shears.

Burns are produced either from an arc or by the heating of the tissues of the body by the current. In case burns are produced it is very necessary not to touch or irritate them. They should be protected from the air by a soft dressing, such as carron oil (a mixture of limewater and linseed oil), baking soda (teaspoonful to a pint of water), or a paste of flour and water. A dry or charred wound should never be covered by a liquid dressing, but simply with a clean cloth.