Which safety practice is essential when working with high voltage?

The use of insulated tools and equipment is essential when working with high voltage because these tools are specifically designed to protect the user from electrical shock. Insulated tools have materials that can withstand high voltages, providing a barrier between the user and the source of electricity. This is crucial in any high voltage environment, where even a small mistake can lead to serious injury or fatality.

While personal safety gear is important, it alone does not prevent electrical shock; working in groups can enhance safety, but it relies on effective communication and coordination. Regular breaks to combat fatigue are beneficial for maintaining overall safety and focus but do not directly address the specific hazards of high voltage work. Thus, using insulated tools directly mitigates the risk associated with high voltage, making it the most critical practice.