Background: Teachers are not trained or feel prepared for urgent action. Nevertheless, the presence of children with health problems is relevant. We identified vital health risk problems and complications among students, as well as the related training and perception of teachers. Methods: An explanatory sequential design was employed. The study sample consisted of a cross-sectional study of an intentional nonprobabilistic sample of 3246 teachers in the quantitative phase, and a total of 16 semistructured interviews were conducted in its qualitative phase. Results: 56.6% (1837) of teachers show high concern about facing such situations and only 0.6% (19) feel appropriately trained. For 81.8% (2556), the existence of school nursing would be quite relevant. The presence of nursing professionals in schools could lead to an improvement in the quality of life of both the students and teachers. Conclusions: There is a significant percentage of children with diseases that often require specific care and there is a high probability that teachers, throughout their professional lives, have to deal with situations of vital urgency. The presence of professionals in educational centres seems to be a relevant option. These data suggest that it is necessary for nurses to establish a pilot programme for the incorporation of professional nurses in educational centres to determine its implications, benefits in health prevention and promotion issues, as well as costs.