Which of the following must not happen while hot work is being conducted?

During hot work operations, it is critical to maintain the integrity of fire protection systems. Impairing the sprinkler system poses a significant risk because it reduces the ability to control or extinguish a fire should one occur. Fire protection systems, including sprinklers, play a vital role in providing a rapid response to fire hazards that may arise during activities such as welding, cutting, or grinding. Any impairment to these systems can lead to catastrophic outcomes, as the primary means of fire suppression would be ineffective.

On the other hand, using protective equipment, keeping a fire watch, and ensuring proper ventilation are essential practices that enhance safety during hot work. Personal protective equipment (PPE) helps to shield workers from potential hazards, while a fire watch is responsible for monitoring the area for signs of fire during and after the work. Proper ventilation is important to prevent the accumulation of hazardous fumes and ensure a safe working environment.