F1: Research Roundup Hazard Recognition/Heat Related Issues

Studies have shown that the risk of occupational heat-related illnesses, including heat stroke, is increased on the first day and first week of heat exposure. The proposed OSHA Standard for Heat Injury and Illness Prevention includes a prescribed acclimatization schedule. The schedule includes 20% of a normal work shift exposure to heat stress on the first day, 40% on the second day, 60% on the third day, and 80% on the fourth day. Data gaps exist in the scientific literature about what acclimatization schedules work best for adapting to hot environments. This study examined the physiological responses of volunteers exposed to heat stress following the OSHA protocol. The physiological parameters measured were core body temperature and heart rate. Baseline measurements were made during two hours of walking on a treadmill in an environmental enclosure set to a specific WBGT range. Following at least a week, the subjects were tested over 5 successive days walking for 24 minutes on the first day, 48 minutes on the second day, 72 minutes on the third day, 96 minutes on the fourth day, and 120 minutes on the fifth day. Data were analyzed to determine any change in core body temperature and heart rate over two hours of exposure to heat stress.  

Conventional strategies for heat stress management have relied on local Wet Bulb Globe Temperature (WBGT) or heat index tracking. Although effective in assessing ambient temperature and humidity conditions, these guidelines may underestimate the impact of heat exposure on individual workers. Recent advances in wearable sensors have enabled real-time and noninvasive measurement of sweat loss and hydration status. These sweat-sensing systems have recently been deployed in working environments and incorporated into heat illness prevention programs. We present a case study of how hydration data can be used as part of a heat prevention program to change behavior to reduce heat exposure. The talk will focus on the lessons learned in implementation, user adoption, effective strategies, and what could be improved.