The integration of digital devices in education has been widely practised throughout the world. The vast availability of digital devices enables teachers to prepare and deliver subject content in different ways. Despite the availability of various digital devices in the Fourth Industrial Revolution, some teachers still experience "technostress" in terms of the delivery of subject content. The COVID-19 pandemic severely disrupted the delivery of subject content causing a tremendous change within educational settings globally. To explore secondary school teachers' use of the Technological Pedagogical and Content Knowledge model in delivering content, this study used a qualitative multiple case study research design. The empirical data were collected from seven secondary school teachers and were thematically analysed. The findings from non-participant observation and semi-structured interviews assisted in revealing teachers' use of the Technological Pedagogical and Content Knowledge model in delivering subject content. The findings point to a lack of digital devices within the selected secondary schools as well as teachers' limited knowledge of online delivery of content. It is recommended that schools be provided with ICT infrastructure and be taken on board with training on how to use them.