Figure 2.

Temporal summation of heat pain in fibromyalgia subgroups. This figure depicts the time course of pain perception during the tonic thermal noxious stimulation in fibromyalgia (FM) patients receiving experimental temperatures lower and higher than 45°C. We can clearly see a temporal summation effect in the FM ≥ 45°C subgroup that was not present in the FM < 45°C subgroup; error bars refer to standard errors.