Thermal physics is well-known for presenting conceptual challenges that prove highly resistant to traditional teaching and learning. These challenges often stem from students only developing a surface-level understanding of phenomena, without forming deeper generalisations between concepts. This investigation explores whether the use of metacognitive strategies in lessons (specifically, concept mapping and prompted planning and evaluation of problem solving) may promote Year 12 students to consciously examine their own understanding of concepts and, in turn, develop more coherent and valid knowledge schemata. Results show that, during a five-lesson intervention, students displayed subtle signs of increased use of metacognitive skills, particularly those relating to planning and to linking concepts with prior knowledge. This paper argues that such strategies therefore warrant consideration for inclusion in teachers’ classroom practice, but that significant further work would be needed to prove a causal link to improved student understanding.