Cooling Effect of Ice Slurry Confirmed for Heatstroke Prevention in Workplaces

Taisho Pharmaceutical Co., Ltd. has revealed through a joint study with Professor Hiroshi Hasegawa of Hiroshima University that consuming 'ice slurry' (a fluid, sherbet-like beverage containing fine ice particles) in hot working environments leads to a decrease in core body temperature and an improvement in cognitive function in human trials. These results demonstrate the effectiveness of using ice slurry in combination with fan-equipped workwear, which is currently used as a heatstroke countermeasure in summer workplace environments. The research findings were presented at the 99th Annual Meeting of the Japan Society for Occupational Health, held from May 27 to 30, 2026. Against the backdrop of record-breaking heat in recent years, heatstroke prevention in the workplace has become an urgent social issue. To strengthen workplace heatstroke countermeasures, the Industrial Safety and Health Regulations were revised in 2025, mandating that employers implement appropriate measures. In response, in addition to managing work hours and replenishing water and salt, body cooling using fan-equipped workwear is widely implemented at work sites. However, despite these measures, the number of casualties due to heatstroke in the workplace reached a record high in 2025, and more practical and effective heatstroke countermeasures are being sought at work sites. In this study, exercise mimicking labor was performed while wearing fan-equipped workwear in a hot environment equivalent to actual outdoor summer working conditions. As a result, it was confirmed that drinking ice slurry lowered core body temperature and forehead skin temperature, and improved cognitive function in the latter half of the exercise. It has been pointed out that a decline in attention in hot environments leads not only to a decrease in productivity but also to injuries and accidents. Therefore, the results of this study indicate that ice slurry can contribute not only to reducing physical burden as a heatstroke countermeasure but also to improving work efficiency and safety.