Pusher assemblies for use in microelectronic device testing systems and methods for using such pusher assemblies are disclosed herein. One particular embodiment of such a pusher assembly comprises a plate having a first side and a second side opposite the first side. An engagement assembly is removably coupled to the second side of the plate and positioned to contact a microfeature device being tested. The pusher assembly can include an urging member proximate the first side of the plate and configured to move the engagement assembly toward the device being tested. The pusher assembly can also include a heat transfer unit carried by the first side of the plate. In several embodiments, the pusher assembly can further include a plurality of pins carried by the engagement assembly such that the pins extend through the plate and engage the urging member to restrict axial movement of the urging member toward the device being tested.