A portable handheld thermo-electric device (10) is used to test for decreased cold pain thresholds or increased sensitivity to cold stimulation (cold hyperalgesia) in a patient. The thermo-electric device (10) comprises a probe (18), a Peltier module (12) and a control unit (16) operable to energize the Peltier module (12) so that the temperature of the probe 18 is variable in a range between a predetermined upper temperature limit and a predetermined lower temperature limit during a test cycle of the thermo-electric device (10). A thermal mass (14) is adapted for thermal contact with an interface side (34) of the Peltier module (12). The Peltier module (12) has thermal properties which enables it to be cooled to a temperature below the predetermined upper temperature limit and thereafter maintain the interface side (34) of the Peltier module (12) at a temperature below the predetermined upper temperature limit for the duration of the test cycle.
