Andersen I, Jensen P L, Junker P, Thomsen A, Wyon D P
Scand J Work Environ Health. 1976 Dec;2(4):256-68. doi: 10.5271/sjweh.2804.
With the use of a climate chamber, the effects of a 3-h exposure to moderate heat stress (23 to 29 degrees C) on the physiology, comfort, and performance of 20 subjects, 10 with slight (group I) and 10 with moderate (group II) ischemic heart disease (IHD), were studied. Twenty matched control subjects were similarly exposed. All of the subjects performed sedentary, mental work throughout the exposure. Humidity was 9 mm Hg; air velocity, 10+/-3 cm per second; and thermal resistance of the clothing, 0.7 clo. Under identical conditions no significant differences in rectal, skin, and finger temperatures or weight loss existed between the three groups, but during heat stress the temperatures and weight loss were always significantly higher than under the control conditions, except for rectal temperatures during the first 2 h. There was no difference between the groups or the two sets of conditions in respiration rate and diastolic blood pressure, but the patients had a significantly lower systolic blood pressure in the third hour of heat stress than under the control conditions. Heart rate and the rate-pressure-product during heat stress were significantly higher in the controls than in the patients. A few patients experienced a slight retrosternal oppression during heat stress, but only one had ECG changes, and none of these symptoms or signs were present under control conditions. Under both sets of temperature conditions the patients were uncomfortable during a longer period of time than the controls, and they were more sensitive to temperature changes, group II being more sensitive than group I. The comfort distribution curve was very narrow for group II. The performance tests were numerical addition, card punching, cue-utilization and creative association. In numerical addition no temperature effect could be shown on the speed of working, but for the patients in group II during heat stress the level of accuracy in the second hour was lower than under control conditions; the trend was the opposite for control subjects. No differences occurred in the first or third hour. In card punching the patients in group II worked significantly more slowly during heat stress than did the control subjects, who improved their performance in heat, as did the paracy with which this task was performed, the patients in group II making significantly more errors in the heat than patients in group I. Cue-utilization did not differ between groups or conditions. Patients performing the creative association test under heat stress supplied significantly fewer unique answers than did patients working under control conditions; no such effect of heat was observed for control subjects. We conclude that patients with IHD are more sensitive to moderate heat stress than healthy control subjects in terms of mental performance and comfort. There are some differences in cardiopulmonary function but no differences in thermoregulation.
使用气候舱，研究了20名受试者（10名轻度缺血性心脏病患者（I组）和10名中度缺血性心脏病患者（II组））暴露于中度热应激（23至29摄氏度）3小时对其生理、舒适度和表现的影响。另外选取了20名匹配的对照受试者进行同样的暴露实验。在整个暴露过程中，所有受试者都进行久坐的脑力工作。湿度为9毫米汞柱；风速为每秒10±3厘米；衣物的热阻为0.7克罗。在相同条件下，三组受试者的直肠温度、皮肤温度、手指温度或体重减轻均无显著差异，但在热应激期间，除前2小时的直肠温度外，温度和体重减轻始终显著高于对照条件下的水平。三组受试者或两种条件下的呼吸频率和舒张压无差异，但在热应激的第3小时，患者的收缩压显著低于对照条件下的收缩压。热应激期间，对照组的心率和心率 - 压力乘积显著高于患者组。少数患者在热应激期间经历了轻微的胸骨后压迫感，但只有1例出现心电图变化，且在对照条件下均未出现这些症状或体征。在两组温度条件下，患者感到不适的时间都比对照组更长，并且他们对温度变化更敏感，II组比I组更敏感。II组的舒适度分布曲线非常狭窄。表现测试包括数字加法、打孔、线索利用和创造性联想。在数字加法测试中，未发现温度对工作速度有影响，但在热应激期间，II组患者在第2小时的准确性水平低于对照条件；对照受试者的趋势则相反。在第1小时和第3小时未发现差异。在打孔测试中，II组患者在热应激期间的工作速度明显慢于对照受试者，对照受试者在热应激下表现有所改善，而执行该任务的辅助条件方面，II组患者在热应激下的错误明显多于I组患者。线索利用在不同组或条件之间没有差异。在热应激下进行创造性联想测试的患者提供的独特答案明显少于在对照条件下工作的患者；对照受试者未观察到热的这种影响。我们得出结论，就脑力表现和舒适度而言，缺血性心脏病患者比健康对照受试者对中度热应激更敏感。心肺功能存在一些差异，但体温调节方面没有差异。
