Recent iterations of online education emphasize gaining a deeper understanding of teachers' professional skills, competencies, and performances. In line with this growing scholarship, the present study adopted an interpretative phenomenological analysis approach and examined Iranian English language teachers' emotion labor in response to online teaching. To this end, data were collected from semi-structured interviews, reflective journals, and narrative frames. Data analysis revealed three themes defining the teachers' emotion labor: clashes in effective student engagement, conflicts in effective material coverage, and tensions in delivering effective assessment. The study shows how online teaching played an overarching role in the multiplicity and fragmented nature of the teachers' emotions and how the teachers engaged in surface and deep acting in accordance with the emerging particularities to respond to institutional expectations. Based on the findings, we provide implications for teacher educators and policymakers to run emotion labor-related professional development courses that account for teachers' emotions and involve them in initiatives responding to their emotion work.