Academic performance is the level of achievement that students reach in their educational activities. It is influenced by several factors that should be analysed and prioritised, especially in engineering courses, characterised by their difficulty and low success rates compared to other careers. This paper analyses the impact of these factors on academic performance during exams in a technical college in southwestern Spain, with a particular focus on environmental conditions, identified as a relevant and independent variable. The results show a significant connection between thermal comfort and academic performance. Temperatures within the comfort range (23–26 °C) improved students’ satisfaction with exams. In contrast, those who experienced thermal discomfort pointed to environmental conditions as the main obstacle to their performance, overcoming factors such as prior preparation and coincidence of exams. These findings underline the importance of optimising the classroom’s thermal environment through strategies that promote a more favourable learning space, improving both students’ well-being and their academic performance.