Heat stress mitigation with ice cooling vests in PPE-clad medical workers: Effects of cooling area and gender differences

Abstract

During the COVID-19 pandemic, many health care workers (HCWs) were required to perform medical tasks in outdoor settings while wearing medical protective clothing. Although personal protective equipment (PPE) is virus-resistant, it can impair the heat dissipation of HCWs. Hence, HCWs face significant heat stress risks while working outdoors. There is an urgent need to find effective ways to reduce heat stress in order to protect the health and safety of HCWs who wear personal protective equipment. In this study, the applicability of two ice-bag cooling vests (ICVs) with varying cooling areas for HCWs wearing PPE was evaluated. Based on the effects of the two ICVs on the thermal comfort of HCWs working outdoors, a cooling strategy for HCWs wearing PPE in outdoor environments was demonstrated. In addition, the gender difference in cooling demand was examined. Eighteen participants took part in the outdoor field study. The results indicated that using ice-bag cooling vests could reduce sweat loss by 27.3–39.4 % (0.09–0.13 kg) and the mean skin temperature by 0.25–0.95 °C. Cooling the back is more effective than cooling the abdomen in reducing overall thermal sensation. The area of discomfort corresponds to the area of sweating. Sweating is an important factor influencing the comfort of HCWs. ICVs could provide some comfort relief for 15–30 min. Gender differences in thermal sensation disappear after 30 min of exposure. The ICVs are recommended for use in future emergency situations. The findings of this study are beneficial to the health and safety of outdoor-working HCWs wearing personal protective equipment.