Peripheral vascular disorder is one of the most important symptoms in diagnosing vibration disease. Several kinds of tests have been introduced to evaluate the peripheral vascular function. Among those tests, cold water immersion test has been mostly applied. In Japan, the generally used method is to measure the skin temperature of one finger of the hand immersed up to the wrist joint in water at 5 degreesC for 10 minutes. However, because the suffering during the test is so severe and some unfavorable warning symptoms have been observed during group examinations, a safer and milder method is more desirable. In order to examine the applicability of the test by using water at 10 degreesC in comparison with that at 5 degreesC, and to know the degree of suffering during the tests, a comparative study was performed. Sixteen students and 29 patients with vibration disease joined in this study. The results suggest that water at 10 degreesC can be effective stimulus, if the immediate rewarming response is used for evaluation. The self-rating scores revealed that the suffering was milder in case of water of 10 degreesC than at 5 degreesC for both the students and the patients. And the patients seemed to suffer more from chest discomfort than the students.