Fig. 4. Mean thermal detection thresholds in the PHN-affected and mirror-image unaffected sites. As a group, the subjects demonstrated hypoesthesia to warmth and cool sensation, and hypoalgesia to heat pain and cold pain. Thermal sensory tests were conducted in the same locations as the mechanical testing. Sensory thresholds for warmth, coolness, heat pain, and cold pain sensations were determined three times each. The median of the responses to the application of the consecutive stimuli was considered as the threshold at a given site. The base temperature (30°C) changed at a ramp rate of 1°C/s (cutoff temperatures = 0°C and 53°C). Data are mean ± SEM. Numbers indicate number of subjects tested for each modality. Data from all subjects are included for calculation of group means, except those whose heat and cold thresholds in the unaffected, mirror-image skin were > 53°C or < 0°C, respectively.