Cutaneous thermosensitivity differences among the face, hand and thigh appear not to exist for skin blood flow during normothermic states

Meeting abstrac

Cutaneous thermosensitivity differences among the face, hand and thigh appear not to exist for skin blood flow during normothermic states

Meeting abstrac

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 °C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 °C, with only the more protective ensemble investigated at 30 and 35 °C. At 35 °C, auditory canal temperature rose at 0.02 °C min(-1) (SD 0.005), deviating from all other trials (p \u3c 0.05). The thresholds for moderate (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in ~10 h at 30 °C, but should not occur at 25 °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\u27s 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 (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 and 180 min, respectively

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 °C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 °C, with only the more protective ensemble investigated at 30 and 35 °C. At 35 °C, auditory canal temperature rose at 0.02 °C min(-1) (SD 0.005), deviating from all other trials (p \u3c 0.05). The thresholds for moderate (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in ~10 h at 30 °C, but should not occur at 25 °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\u27s 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 (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 and 180 min, respectively

Sweat gland recruitment following thermal and psychological stimuli

Eccrine sweat glands are present across almost the entire body surface. The distinction between glabrous (hairless) and non-glabrous skin has frequently been used to describe differences in human sudomotor function and, in particular, to help differentiate between the thermal and nonthermal mechanisms that modulate sweat secretion. Indeed, the widely accepted consensus is that psychological (psychogenic) sweating is limited to the glabrous regions, while thermally induced secretion occurs only from non-glabrous surfaces (Iwase et al., 1997). Furthermore, it is frequently assumed that independent central controllers, efferent pathways and different neurotransmitters activate the sweat glands within each of these regions. A recent research focus of the current laboratory has been to evaluate the veracity of these assumptions

Motorcycle protective clothing: physiological and perceptual barriers to its summer use

Despite strong evidence of protective benefits, thermal discomfort is a key disincentive to motorcyclists wearing protective clothing in hot conditions. This paper presents some findings from our studies concerning the thermal management properties of motorcycle protective clothing and their physiological impact in hot conditions. The thermal and vapour permeability and abrasion resistance properties of motorcycle protective clothing were investigated in laboratory tests. The physiological and cognitive impact on humans was investigated using objective and subjective measures under controlled climate conditions and in a real-world riding trial. The aims were to determine: (i) if associations existed between thermal management and the abrasion-resistance properties of a range of commonly available, all-season motorcycle protective suits, (ii) the extent of the thermal load imposed by motorcycle clothing worn in average Australian summer conditions, and (iii) the impact of that thermal burden on psychophysical function. The results demonstrated significant physiological strain for motorcyclists wearing protective clothing in hot conditions. Wide variations in the thermal characteristics and abrasion resistance properties of the suits tested were identified. Ongoing work is investigating the impact that elevated thermal discomfort and physiological thermal strain can have on riding performance and the potential for clothing features, such as ventilation ports to reduce thermal discomfort. These results will determine thresholds for the thermal qualities of motorcycle clothing required for an acceptable compromise between user comfort and injury protection. The outcome will inform industry and consumer information programs about the performance required of motorcycle protective clothing suitable for use in hot conditions

Design data for footwear: sweating distribution on the human foot

Purpose – The purpose of this paper is to provide footwear designers, manikin builders and thermo-physiological modellers with sweat distribution information for the human foot. Design/methodology/approach – Independent research from two laboratories, using different techniques, is brought together to describe sweat production of the foot. In total, 32 individuals were studied. One laboratory used running at two intensities in males and females, and measured sweat with absorbents placed inside the shoe. The other used ventilated sweat capsules on a passive, nude foot, with sweating evaluated during passive heating and incremental exercise to fatigue. Findings – Results from both laboratories are in agreement. Males secreted more than twice the volume of sweat produced by the females (p<0.01) at the same relative work rate. Both genders demonstrated a non-uniform sweat distribution, though this was less variable in females. Highest local sweat rates were observed from the medial ankles (p<0.01). The dorsal foot sweated substantially more than the plantar (sole) areas (p<0.01). Sweating on the plantar side of the foot was uniform. Wearing shoes limited the increase in sweat production with increasing load, while the sweat rate of uncovered feet kept increasing with work and thermal load. Practical implications – The observed variation in sweat rate across the foot shows that footwear design should follow the body mapping principle. Fabrics and materials with different properties can be used to improve comfort if applied to different foot surfaces. The data also demonstrate that foot models, whether physical (manikins) or mathematical, need to incorporate the observed variation across the foot to provide realistic simulation/testing of footwear

Motorcycle protective clothing: physiological and perceptual barriers to their summer use

Despite strong evidence of protective benefits, thermal discomfort is a key disincentiveto motorcyclists wearing protective clothing in hot conditions. This paper presentssome findings from our studies concerning the thermal management properties ofmotorcycle protective clothing and their physiological impact in hot conditions.The thermal and vapour permeability and abrasion resistance properties of motorcycleprotective clothing were investigated in laboratory tests. The physiological andcognitive impact on humans was investigated using objective and subjective measuresunder controlled climate conditions and in a real-world riding trial. The aims were todetermine: (i) if associations existed between thermal management and the abrasionresistanceproperties of a range of commonly available, all-season motorcycleprotective suits, (ii) the extent of the thermal load imposed by motorcycle clothing wornin average Australian summer conditions, and (iii) the impact of that thermal burden onpsychophysical function.The results demonstrated significant physiological strain for motorcyclists wearingprotective clothing in hot conditions. Wide variations in the thermal characteristics andabrasion resistance properties of the suits tested were identified. Ongoing work isinvestigating the impact that elevated thermal discomfort and physiological thermalstrain can have on riding performance and the potential for clothing features, such asventilation ports to reduce thermal discomfort. These results will determine thresholdsfor the thermal qualities of motorcycle clothing required for an acceptable compromisebetween user comfort and injury protection. The outcome will inform industry andconsumer information programs about the performance required of motorcycleprotective clothing suitable for use in hot conditions