熱應力是個廣為人知的工業安全衛生危害。若勞工持續暴露於熱環境,且無法改變其工作與休息時間或補充身體所需的水分及電解質時,則體內的熱蓄積會持續增加,進而使體內熱調節機制失調,因而出現熱衰竭、熱經攣、熱暈厥或中暑等熱疾病症狀。目前熱應力大部分都以綜合溫度熱指數(Wet-Bulb Globe Temperature, WBGT)評估外在環境溫度,然而WBGT並無法有效指出勞工之生理熱應變(皮膚溫度、核心溫度、心搏率等)。 本研究利用即時熱應力個人監控器、Polar心率錶、WBGT指數偵測儀、風速計及電子體重計,收集3名在鑄造工廠工作的作業者在不同季節(夏季、冬季)及不同時段自變項之生理指數。本研究探討各自變項對皮膚溫度、耳溫、小環境溫度、心搏率、出汗量、主觀熱感覺及主觀知覺施力之影響,並探討生理指數之相關性。 研究結果顯示為季節與時段對受測者之皮膚溫度、耳溫、心搏率、出汗量、主觀熱感覺及主觀知覺施力量表皆有顯著影響。而相關分析黑球溫度與皮膚溫度、耳溫、心搏率及出汗量顯著正相關。
Heat stress is a well-known safety and health hazard. If the workers are continuously exposing to thermal environment and can’t change work to rest ratio, drink enough water, or keep electrolytes in balance, the accumulation of heat will lead to failure of temperature regulation mechanism. In addition, heat stress can result in heat exhaustion, heat cramps, heat syncope, heat stroke, or other heat related illnesses. Currently, the exposure surveillance of heat stress for workers is still limited to a general assessment of the environment climate using the Wet-Bulb Globe Temperature (WBGT) index. However, physiological responses (e.g. skin temperature, core temperature, or heart rate) of workers due to heat stress cannot be reflected by the WBGT index. This research used real-time personal heat stress monitor, Polar heart rate monitor, WBGT meter, anemometer, and electronic scales to collect physiological responses of three precision casting workers in field for summer and winter seasons and at different time periods in a day. Then, this study investigated the effects of independent variables on skin temperature, ear temperature, environmental temperature, heart rate, and the amount of sweat. Also, this study investigated the correlation between physiological responses. The results show that the effects of season and time period were statistically significant on skin temperature, ear temperature, heart rate, the amount of sweat, and subjective thermal sensation and perceived exertion. The Pearson correlation analysis results showed significant positive correlation between the black-bulb temperature and skin temperature, ear temperature, heart rate and the amount of sweat.