Microelectronic devices with improved heat dissipation, methods of making microelectronic devices, and methods of cooling microelectronic devices are disclosed herein. In one embodiment, the microelectronic device includes a microelectronic substrate having a first surface, a second surface facing opposite from the first surface, and a plurality of active devices at least proximate to the first surface. The second surface has a plurality of heat transfer surface features that increase the surface area of the second surface. In another embodiment, an enclosure having a heat sink and a single or multi-phase thermal conductor can be positioned adjacent to the second surface to transfer heat from the active devices.