 While most propositional temporal logics are decidable, adding some syntactic or semantic features can make them explode computationally and become undecidable. The most common causes of undecidability of temporal logics, besides combinations with other expressive logics, include: grid-like models; temporal operators along multiple time-lines; products of temporal logics; interval-based logics with no locality assumptions; time reference mechanisms, such as hybrid reference pointers and freeze quantifiers; arithmetic features, such as time addition, exact time constraints, etc. However, there are various ways to tame temporal logics and restore decidability, such as adding syntactic and parametric restrictions (e.g. on the number of propositional variables or the depth of nesting), imposing suitable semantic restrictions (e.g. locality for interval logics), identifying decidable fragments (e.g. the two-variable fragment FO\(^{2}\) of classical first-order logic, guarded fragments, monodic fragments), etc.