sleep; science teaching; public health indicator; blue screen.

From the 21st century onwards, especially with the popularization of smartphones, teachers were faced with yet another challenge to be overcome in the classroom: sleepy students, which can lead to decreased concentration, increased irritability, hormonal irregularity and difficulty in the teaching-learning process. Faced with this reality, and understanding the importance of the sleep-wake cycle for maintaining health and quality of life, the present work proposes the analysis of students' sleep hygiene, through a didactic sequence addressing the biological rhythm, specifically the sleep-wake cycle. This research, of a qualitative nature, had 7th grade students from a municipal school in Nova Cruz-RN as subjects, bearing in mind that the development of skills on the public health indicator is present in this school year. The results obtained through questionnaires and sleep diary were analyzed using Bardin's Content Analysis. The didactic sequence developed based on the three pedagogical moments, validated and applied, gave rise to our Educational Product, to be used as support material for the Basic Education teacher. The results show that, in general, students make excessive use of blue light screens at night and, consequently, end up sleeping later, even though they need to wake up early to go to school. Furthermore, it was identified that although most students know at least some healthy habits for a good night's sleep, they do not seem to apply them in their daily routine and do not understand the importance of sleep for maintaining quality of life. Throughout the classes, and based on the activities proposed, such as expositive- dialogued classes with subsequent debate, presentation and discussion of videos, preparation and presentation of a seminar for the school community, among other practical activities, we were able to observe great motivation and participation of the students. Thus, although we understand that changes in habits require time and persistence, we can infer that our objectives of analyzing students' sleep hygiene, counterpointing questions that could lead them to reflections, seem to have been achieved to some extent. We also highlight the need to include this theme during the organization of teachers' planning, since most of the time it is not addressed in textbooks.