احمد جامه خورشید

Cooling vests containing phase change materials (PCMs) are one way to confront the effects of personal heat. These vests reduce the body's temperature by absorbing the excess body heat with PCM. This study aimed to investigate the performance of a cooling vest and its efficacy on physiological parameters in extremely hot and humid conditions, which are the operating conditions of the oil and gas industry in the Persian Gulf region. The heart rate, systolic and diastolic blood pressure, thermal sensation, and sweating rate of nineteen volunteers were measured in a climatic chamber with a temperature of 40 °C and relative humidity of 45%. The results indicated that the vest did not have a significant effect on heart rate and systolic and diastolic blood pressure over time. However, it affects the thermal sensation and sweating rate. In order to find the performance duration of the vest used, one package of PCM with a melting temperature of 28 °C was simulated. In general, it can be concluded that this type of cooling vest under the tested climatic conditions does not have a 3-hour performance claimed by the manufacturer. Nevertheless, this cooling vest has a significant effect on the subject's thermal sensation for 20 min. These findings may be applied in the future design of cooling vests under mentioned environmental conditions.