Energy poverty is a growing multidimensional concern worldwide, with children and young people particularly vulnerable. This age group spends a significant amount of time in both their houses and school buildings. Still, there has been little research on the dual vulnerability to inadequate thermal comfort conditions in these two environments. In Portugal, the exposure to inadequate thermal comfort in school buildings varies due to disparities in renovation efforts: while some schools have undergone renovations to improve thermal comfort, others have not. This work aims to assess upper secondary school students’ perception of energy poverty at home and thermal comfort inside classrooms. The study employed two complementary components: surveys of a statistically significant sample of students from one renovated and one non-renovated schools located in the Lisbon district for a more focused insight, and surveys from students from different schools across Portugal, to have a more exploratory perspective. The first segment of the methodology was complemented with interviews and surveys with other school stakeholders to understand their perceptions of this issue. The results indicate that between 4.2-14% of students live in permanent discomfort (uncomfortable both in school and at home). Despite the discomfort still observed in students from the renovated school, it is possible to say that the renovation attenuated this. Students with health conditions and disadvantaged backgrounds were more likely to report discomfort than those who did not. This study raises awareness of a vulnerable group and underscores the importance of studying energy poverty and thermal comfort at the local level, considering the variations between schools, socio-demographics, and climatic zones. This study provides valuable insights into the issue of energy poverty among young people. It addresses the need to incorporate this age group in energy-related policies, to involve the students in the decision process regarding the classroom' temperature and that schools are places that may serve as a refuge from energy poverty to this age group.