A computing system includes a number of memory modules and temperature sensors. Each temperature sensor measures a temperature of a memory module. In such a computing system a garbage collector during garbage collection, determines whether a temperature measurement of a temperature sensor indicates that a memory module is overheated and, if a temperature measurement of a temperature sensor indicates a memory module is overheated, the garbage collector reallocates one or more active memory regions on the overheated memory module to a non-overheated memory module. Reallocating the active memory regions includes copying contents of the active memory regions from the overheated memory module to the non-overheated memory module.