Thermal and Cardiovascular Strain Imposed by Motorcycle Protective Clothing Under Australian Summer Conditions.

Motorcycle protective clothing can be uncomfortably hot during summer, and this experiment was designed to evaluate the physiological significance of that burden. Twelve males participated in four, 90-min trials (cycling 30 W) across three environments (25, 30, 35 degrees C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 degrees C, with only the more protective ensemble investigated at 30 and 35 degrees C. At 35 degrees C, auditory canal temperature rose at 0.02 degrees C min(-1) (SD 0.005), deviating from all other trials (p < 0.05). The thresholds for moderate (> 38.5 degrees C) and profound hyperthermia (> 40.0 degrees C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in similar to 10 h at 30 degrees C, but should not occur at 25 degrees C. These outcomes demonstrate a need to enhance the heat dissipation capabilities of motorcycle clothing designed for summer use in hot climates, but without compromising impact protection. Practitioner's Summary: Motorcycle protective clothing can be uncomfortably hot during summer. This experiment was designed to evaluate the physiological significance of this burden across climatic states. In the heat, moderate (> 38.5 degrees C) and profound hyperthermia (> 40.0 degrees C) were predicted to occur within 105 and 180 min, respectively.