This document, which is intended to serve as a guide for work force preparation program providers, details the Illinois occupational skill standards for programs preparing students for employment in jobs in the heating, ventilation, air conditioning, and refrigeration (HVAC/R) industry. Agency partners involved in this project include: the Illinois State Board of Education, Illinois Community College Board, Illinois Board of Higher Education, Illinois Department of Commerce and Community Affairs, and the Illinois Department of Employment Security. The document begins with a brief overview of the Illinois perspective on occupational skill standards and credentialing, the process used to develop the skill standards, and assumptions underlying the standards. Presented next are skill standards for 75 tasks typically performed by HVAC/R technicians. Each skill standard statement contains the following components: (1) the actual skill standard (including the conditions of performance, work to be performed, and performance criteria); (2) performance elements; and (3) performance assessment criteria. The tasks for which skill standards are provided are organized into the following categories: (1) accident and emergency procedures; (2) evaluation and replacement of air conditioning units, heat pumps, and refrigeration; and (3) evaluation and inspection of furnaces and air handlers. Appended are the following: list of contents of the HVAC/R technician tool kit; glossary; lists of Transportation, Distribution, and Logistics Subcouncil and HVAC/R Technician Cluster Standards Development Committee members; and list of necessary workplace skills. (MN)