بررسی سطح استرین سرمایی و ارتباط آن با پاسخ های فیزیولوژیک در شاغلین مکانیک خودرو

Introduction: Continuous exposure to cold air is considered to be a hazardous agent in the workplace in cold seasons. This study aimed to determine the level of cold strain and relation with physiological responses in auto mechanic employees in cold seasons. Method: This cross-sectional study was conducted in the winter of 2017 on auto mechanic employees in Hamadan city. Physiological responses during daily activity were measured in accordance with ISO 9886 standard method.  Based on the results of core and skin temperatures, cold strain index were determined. Sensorineural test to determine the level of numbness in the fingers of workers by monofilament kit was performed. Environmental parameters of air were measured simultaneously. Data was analyzed using SPSS 21 software. Result: Results showed that there is a significant relationship between cold stain index score with physiological responses such as heart rate (r=-0.39, p<0.05) and systolic blood pressure (r=-0.57, p<0.05) and diastolic blood pressure (r=-0.38, p<0.05). By reducing the temperature of dry air, a cold Strain Index value was also increasing(r=-0.93, p<0.05). The results showed that 62% of workers had numbness symptoms in fingers and there is a significant relationship between numbness of fingers with air temperature (r=0.74, p<0.01) and cold strain index(r=0.84, p<0.01). Conclusion: Cold strain index along with the acceptable reliability is indicated of physiological responses of workers exposed to cold. More than the half of workers with the numbness symptoms in fingers had affects their physical performance at work.