; or (B) the presence of heat in a work setting. (5) The term heat-related illness means a material impairment of health that occurs due to heat stress. (6) The term heat-related injury means an injury caused by exposure to heat or sources of heat or occurring as a result of heat stress. (7) The term Institute means the National Institute for Occupational Safety and Health. (8) The term Secretary means the Secretary of Labor. (9) The term worker heat protection standard means a standard that regulates employee exposure to heat stress and prevents heat-related illness and injury by requiring conditions or the adoption or use of one or more practices, means, methods, operations, or processes reasonably necessary or appropriate to provide employment and places of employment that are safe or healthful.