Thermal control units (TCU) for maintaining a set point temperature on an IC device under test (DUT) are provided. The units include a pedestal assembly comprising a heat-conductive pedestal, a fluid circulation block, a thermoelectric module (Peltier device) between the heat-conductive pedestal and the block for controlling heat flow between the pedestal and fluid circulation block, and a force distribution block for controllably distributing a z-axis force between different pushers of the TCU. Alternatively, instead of a thermoelectric module, a heater can provide heat to the DUT. Optionally, a swivelable temperature-control fluid inlet and outlet arms may be provided to reduce instability of the thermal control unit due to external forces exerted on the TCU such as by fluid lines attached to the fluid inlet and outlet arms. Also optionally, an integrated means for abating condensation on surfaces of the TCU during cold tests may be provided.