35 Pa. C.S. § 7422
The following words and phrases when used in this subchapter shall have the meanings given to them in this section unless the context clearly indicates otherwise:
"Discipline." The taking of an action against an employee which adversely affects his regular pay to an extent greater than permitted by section 7425 (relating to lost time), his job status, his opportunity for promotion or his right to any benefit granted by the employer to other similarly situated employees.
"Discriminate." To discharge or to discipline in a manner inconsistent with the employer's treatment of other similarly situated employees who are injured in the course of their employment or related activities.
"Employer." An individual, partnership, association, corporation, business trust or a person or group of persons acting directly or indirectly in the interest of an employer in relation to any employee.
"Line of duty." Going to, coming from or during fire prevention and safety activities which includes fire prevention, first aid, rescue and salvage, ambulance service, fire police work, assistance at accidents, control of crowds both on the fire grounds and at occasions of public or general assembly, animal rescue, abatement of conditions due to storm, flood or general peril, abatement or removal of hazards to safety and other activities as are commonly undertaken by fire companies, ambulance services or rescue squads or their affiliated organizations.
35 Pa.C.S. § 7422