Final answer:
When using hand signals, visual contact with the operator must be maintained for safety. In electrical work, one-handed operation reduces the risk of serious injury by preventing a conductive path across the heart.
Step-by-step explanation:
When using hand signals, you must always keep visual contact with the operator. This is especially important when working around heavy machinery or in situations where there is a potential for hazardous conditions. Keeping eye contact with the operator ensures that communication is continuous and that any signals given are received and understood in a timely manner. This can prevent accidents and ensure the safety of everyone involved.
As for working with high-power electric circuits, the advice to work "one-handed" or "keep one hand in your pocket" is a sensible safety precaution. This method reduces the risk of creating a conductive path across the heart, which could lead to a fatal electric shock if both hands were engaged and became part of the circuit. Limiting exposure to electric current by using just one hand can significantly reduce the risk of serious injury or death.