This paper describes qualitative research into difficulties university freshmen displayed when 'forced' to use thermodynamic 'concepts,' or rather 'words,' in a thermodynamic context which was, at that time, not (yet) their own context. The research also aims at the identification and the naming of students' proto-thermodynamic context(s), focused on their concepts of work and heat, and taking a thermo-dynamic basic context of work and heat, previously described as an objective of education, as a frame of reference.Three 'rounds' of research were performed in three successive years, each elaborating on the preceding one. The first 'round' concentrated mainly on students' general problems with the thermodynamic concept of heat in a thermodynamic context. The second and the third concentrated mainly on the way a 'transition' from a commonplace concept of work in an ordinary life context to a scientific concept of work is suggested in a much used Dutch secondary school method of physics education. Our first conclusion is that the observed freshmen used 'heat' and 'work' in what we have named a 'thermochemical context'; this can be seen as a proto-thermodynamic context. In addition, they had great difficulties with the thermodynamic system concept. Both conclusions appear to be interrelated.Finally, a possible 'educational road' from this proto-thermodynamic students' context to a 'genuine' thermodynamic context is suggested.