In this talk, I will address the widespread phenomenon of metastability, ubiquitous in a large class of dynamical systems with two or more locally stable states. In particular, in a stochastic point of view, I will explain the specific role of the low-temperature regime which triggers the metastable feature of the stable states. Then, I will provide a few examples of such phenomena in specific concrete models. The talk is partially based on joint works with Insuk Seo and Jung-Kyoung Lee.