SummaryGPS-Disciplined Clocks (GPSDCs) are sensitive to their environment in many ways, and the susceptibility varies with different GPSDC designs. In the short term, temperature shocks can perturb the frequency of the disciplined local oscillator, causing shifts in the time output. Assuming the GPS receiver module is not separately impacted, GPSDC will return to its steady-state time and frequency setpoint, at least until the next environmental shock. We have tested three commercially available GPSDCs with varying results. Performance of these devices in various conditions will be described along with mitigation strategies, including variance of the control loop parameters.