We have studied characteristics of subjects that could potentially influence quantitative sensory measurements in 156 non-neuropathic individuals. All subjects had measurements of vibration perception at the hallux and index finger with the vibration sensitivity tester and measurements of cool and warm perception at the hallux with the thermal sensitivity tester. Age, height, and skin temperature were all inversely related (P less than 0.05) to vibration sensitivity at the hallux, while age was inversely related (P less than 0.01) to vibration sensitivity at the index finger. In multiple regression analyses the significant associations persisted (P less than 0.01). Neither cigarette smoking nor the occasional use of alcohol were related to the quantitative sensory indices. These data indicate that age, height, and skin temperature should be considered in the assessment of vibration perception and that thermal sensitivity is relatively resistant to these factors.