The skin temperature effect of vibratory stimulation was studied in 28 healthy subjects. Vibration (50 Hz or 100 Hz) was applied to the volar surface of the left forearm for 15 min. Skin temperature of the bilateral forearms was measured before and immediately after cessation of vibration and at 5 and 10 min postvibration. Vibration at 100 Hz for 15 min on all 28 subjects was associated with a temperature increase of 4.20 +/- 0.79 degrees F that was significantly (P less than 0.01) higher than that in the controls (0.38 +/- 0.33 degrees F). Skin temperature decreased to previbration levels by 50 min of postvibration. The 11 subjects who received 50-Hz vibration for 15 min showed a skin temperature increase (0.75 +/- 0.23 degrees F) in the vibrated forearm significantly (P less than 0.01) higher than that in the control forearm (0.11 +/- 0.17 degrees F). All measurements decreased to previbration skin temperatures by 10-min postvibration. Vibration at 100 Hz also produced skin erythema in all subjects, whereas 50-Hz vibration produced no erythema. The mechanism by which 100-Hz vibration relieves pain is largely unclear, but it could be associated with increased skin temperature and erythema.