A heat exchange system can include a heat exchange unit and a magnetic element. The heat exchange unit can have a housing and a heat exchange surface configured to thermally couple to a subject of heat exchange. The housing can define an outer surface spaced apart from the heat exchange surface. A magnetic element, a ferrous element, or both, can be positioned within the housing. A coupling agent can have a complementary magnetic element, ferrous element, or both. The coupling agent can interact with the magnetic element, the ferrous element, or both, positioned within the housing. The coupling agent can be coupled to a substrate to retain the heat exchange unit relative to the substrate.