Which safety measure should be followed when operating a guillotine?

Ensuring guards are positioned is a critical safety measure when operating a guillotine. Guards serve to prevent accidental contact with moving parts and to protect the operator from potential hazards associated with the blade's operation. Proper use of guards minimizes the risk of injury and enhances safety by keeping body parts at a safe distance from the dangerous areas of the equipment.

Positioning guards correctly allows operators to focus on their tasks without the distraction of worrying about slipping or misusing cutting techniques that could lead to accidents. Furthermore, the guards can help contain any debris or material that may be ejected during the cutting process, thereby preventing not only personal injury but also damage to the surrounding work environment or other personnel in the vicinity.

The other choices do not prioritize operator safety as effectively as ensuring guards are positioned. For instance, retrieving metal from behind the machine could expose the operator to hazards without proper guards in place. Working with multiple people at the same time can create confusion and increase the likelihood of accidents, especially if everyone is not clearly aware of their roles around the machine. Finally, cutting heavy gauge steel, while sometimes necessary, does not inherently incorporate safety measures and could lead to increased risk if proper precautions like guarding are not maintained.