Maximal voluntary contraction (MVC) in hot (dark columns) and control (white columns) conditions. Left panel: Maximal torque produced during the MVCs. Right panel: Percentage of voluntary activation (VA) during the MVCs. HOT-core: passive hyperthermia in hot ambient conditions. HOT-skin: local modification of skin temperature. NS: No significant difference (η2 ≤ 0.08, p ≥ 0.36). * large (η2 = 0.67) and significant (p < 0.001) difference.