We consider the possibility of defining a general mathematical framework for the homogeneous modeling and analysis of heterogeneous spatio-temporal computations as they occur more and more in modern computerized systems of systems. It appears that certain fibrations of posets into posets, called here spatio-temporal domains, eventually provide a fully featured category that extends to space and time the category of cpos and continuous functions, aka Scott Domains, used in classical denotational semantics. Work partially supported by Inria center Bordeaux-Sud-Ouest, from September 2016 to February 2017. 1 Discrete fibrations and the related notion of categories of elements of a functor on Set are presented in [4] (Section 12.2) or in [27] (Section 1.5).