An enclosed electronic apparatus including a first continuous heat-transfer band forming at least a portion of the exterior surface of the enclosure, with continuous lateral edges on either side thereof, and mounting points on an internal side of the continuous heat transfer band to which a printed circuit board assembly is mountable. A printed circuit board assembly is mounted to the heat transfer band at the mounting points, with a thermally conductive portion forming a thermal path between a heat-producing electronic component of the printed circuit board assembly and the heat transfer band. A thermally conductive gasket between the printed circuit board assembly and the heat transfer band at the mounting points facilitates heat transfer. Opposing first and second enclosure portions seal the respective continuous lateral edges of the heat transfer band against penetration of fluid or debris. It is small, compact, lightweight, rugged and otherwise ergonomic for ease of use and protection from accidental impact caused by, for example, dropping the unit. The reliability of the system is improved because the internal electronic components are protected from moisture, dust, and other liquid or particle contaminants, all while maintaining an internal temperature that is lower than a maximum permissible operating temperature.