出版社:National Institute of Occupational Safety and Health
摘要:Cold-induced vasodilatation (CIVD) and systemic cardiovascular re-sponses due to local finger cooling were studied in 10 healthy subjects at different room (22 and 30°C), water (0, 5, and 10°) temperatures and immersion times (5to 30 min). The skin temperature of the immersed finger, blood pressure, and heart rate were measured before and during the experiments. Conspicuous CIVD com-parable to that at the 0°C test could be obtained even at a water temperature of 5 or 10°C by a rise in room temperature. Under such room and water temperature conditions where marked CIVD appeared, the order of the degree of CIVD in the individuals was almost the same, although the CIVD response was influenced by changes in the room and water temperatures. Furthermore, the order of the mean skin temperature (MSTi) calculated by shortening the immersion time every 1 min remained extremely stable (r > 0.90) even by more than a 20-min reduced immersion time, especially at a water temperature of 5°C. During several minutes after the start of immersion, maximal changes in blood pressure and discomfort due to cold were observed. The degree of these systemic loads in the subjects was reduced with rise in the water temperature. It is concluded that the current local cold tolerance test for 30 min at 0°C can be substituted sufficiently by a 5°C test for 10 to 15 min, and partly even by the 10°C test with the limitation that only MSTi and AT are available as an indicator of the local cold tolerance at higher environ-mental temperatures.