Factors affecting cardiovascular system symptoms were sex, smoking, and work section. Those who were female, smokers, and worked at sizing and in the warehouse had more abnormal symptoms than controls, respectively. Exposure to very low temperature would aggravate heart disease. Swoap et al [39] found that ambient air temperatures below 6C or over 29C resulted in changes in blood pressure and heart rate of mice. In clinical observation, cold exposure induced sympathetic activities causing a higher risk of hypertension [40]. Moreover, Kawahara et al [41] reported that cold exposure was possibly involved in abnormal heart-indicated parameters.