Fig. 1.

Numeric scale ratings (NRS) of thermal sensations (cold, warm/ heat), unpleasantness and pain evoked by placement of the right hand on the thermal grill for 20 s. For insets “cold” and “warm/ heat” hold “0 = neutral” and “100 = worst cold or worst warm/hot”, respectively. For insets “pain” and “unpleasantness” hold “0 = no pain or no unpleasantness” and “100 = worst pain or as unpleasant as can be imagined”, respectively. Three different thermal stimuli were tested: uniform 20 °C, uniform 40 °C and grill (bars tempered alternately at 20 and 40 °C) and each stimulus induced up to four different sensations. Ratings of all subjects (N = 136) are shown as medians with first and third quartiles (box) and range (whiskers, i.e. capped bars). Friedman’s ANOVA with post hoc testing using Wilcoxon’s signed-rank test was performed and significant differences are marked by asterisks