Background To examine relationships between teachers’ experienced classroom demands and autonomic stress reactions, we report the results of a pilot study. Based on an integrative literature review, we identified and described the following situational classroom demands: time and work pressure (including missing rest periods, time pressure, and pressure to get through the subject matter), vocal strain, uncertainty concerning the subject matter, uncertainty concerning didactical decisions, achievement-related diversity in class, lack of social appreciation, disquietude in class, classroom disturbances, behavioral problems of students, insufficient skills and concentration of students, and insufficient motivation of students. Method These identified categories of teachers’ situational classroom demands are the basis for the empirical item identification and selection (Study A). The identified items were used in a single-case, short-term longitudinal study in which we examined relationships between experienced classroom demands and autonomic stress reactions as well as between autonomic stress reactions and affective stress experience via first-order vector autoregressive modeling (Study B). Results Concerning our hypotheses, we found evidence that some of the experienced classroom demands (“I cannot respond to students’ different needs”; “There is disquietude in class”) had time-lagged associations with autonomic stress measures. Furthermore, we found that physiological arousal triggers affective stress experience due to a time-lagged effect. Conclusion The research approach and results of our pilot study can be the basis for further process-oriented research in vocational education and training (VET). From a practical point of view, our results on experienced classroom demands could be used in VET teacher education to prepare student teachers for specific skills to cope with such demands.