Incident energy is a measure of thermal energy at a working distance from an arc fault. It is required for selecting arc rated Personal Protective Equipment (PPE) when work is performing at or near a potential source of an arc flash. The selected PPE arc rating shall be based on the incident energy exposure. The incident energy analysis requirement stipulated in NFPA 70E Article 130.3(B)(1) is the basis for performing an arc flash hazard calculation study (AFHCS).