Heat stress is common among forestry workers, including loggers. PURPOSE: Evaluate the thermal responses to wearing loggers' protective clothing (LPC) while performing moderate intensity exercise in the heat. METHODS: Six healthy male participants performed two trials of treadmill exercise in a warm environmental chamber (35°C, 50% relative humidity [RH]) while wearing either sports clothes (CON) or LPC which included a safety vest, chainsaw chaps, gloves, safety helmet, long trousers, long sleeve shirts, wool socks and boots. The study protocol consisted of two stages of 20 min of exercise at a relative workload of 30% and 50% VO2max. The participants then performed a chainsaw maneuver (sawing motion against a vertical object) for 1 min followed by a recovery period (15 min rest) in the chamber. Study variables included core temperature (Tco), mean skin temperature (Tsk), and heart rate (HR). Data were analyzed by two-way (Trials × Time) repeated measures ANOVA. RESULTS: All 6 subjects (CON) completed 41 min of exercise for CON, but only averaged 38.7 min of exercise (37.7 min treadmill and 1 min chainsaw maneuver) while wearing LPC. Tco in the LPC was higher than CON. However, it was only statistically higher in the recovery time suggesting that wearing LPC in warm environments hinders the recovery of the users. CONCLUSION: Wearing LPC while exercising in the heat at the study specific workloads did impose a significant thermal burden on the wearer evidenced by the elevated HR and Tsk values in the LPC. Tco did not decrease in 15min recovery, showing that LPC imposes a thermal load on the user that may cause heat stress over time if no actions are taken to limit the risk.
Heat; Heat-stress; Forestry-workers; Logging-workers; Thermal-effects; Thermal-reactions; Personal-protective-equipment; Personal-protection; Protective-clothing; Protective-equipment; Physical-exercise; Physiological-effects; Physiological-factors; Physiological-stress; Temperature-effects; Temperature-measurement; Statistical-analysis