GTAs and Lecturers are required to within the first week of classes to submit online an Instructor Substitute Reporting form. You must arrange a substitute for each class at the beginning of the semester in case of an illness or other absence. Talk to the substitute before submitting the form to make sure they are willing and available. University policy states "If prevented from meeting classes or carrying out other academic responsibilities, a faculty member must, if physically able to do so, make satisfactory advance arrangements and communicate, preferably in writing, the nature of these arrangements to the chair." It is the instructor's responsibility to contact their substitute if they cannot meet their class. Class should not be cancelled.