title: Reducing heat stress under thermal insulation in protective clothing: microclimate cooling by a 'physiological' method.
abstract: Heat stress caused by protective clothing limits work time. Performance improvement of a microclimate cooling method that enhances evaporative and to a minor extent convective heat loss was tested. Ten male volunteers in protective overalls completed a work-rest schedule (130 min; treadmill: 3 × 30 min, 3 km/h, 5% incline) with or without an additional air-diffusing garment (climatic chamber: 25°C, 50% RH, 0.2 m/s wind). Heat loss was supported by ventilating the garment with dry air (600 l/min, ≪5% RH, 25°C). Ventilation leads (M ± SD, n = 10, ventilated vs. non-ventilated) to substantial strain reduction (max. HR: 123 ± 12 b/min vs. 149 ± 24 b/min) by thermal relief (max. core temperature: 37.8 ± 0.3°C vs. 38.4 ± 0.4°C, max. mean skin temperature: 34.7 ± 0.8°C vs. 37.1 ± 0.3°C) and offers essential extensions in performance and work time under thermal insulation.
  Heat stress caused by protective clothing limits work time. Performance can be improved by a microclimate cooling method that supports evaporative and to a minor extent convective heat loss. Sweat evaporation is the most effective thermoregulatory mechanism for heat dissipation and can be enhanced by insufflating dry air into clothing.
authors: a Department IV - Military Ergonomics and Exercise Physiology , Central Institute of the Bundeswehr Medical Service , Andernacher Str. 100, D-56070 Koblenz , Germany.
authors: K J
authors: KJ
authors: Glitz
authors: U
authors: U
authors: Seibel
authors: U
authors: U
authors: Rohde
authors: W
authors: W
authors: Gorges
authors: A
authors: A
authors: Witzki
authors: C
authors: C
authors: Piekarski
authors: D
authors: D
authors: Leyk
mesh_terms: D000328:Adult; D000389:Air Conditioning / Q000295:instrumentation / Q000379:methods*; D001833:Body Temperature Regulation; D004867:Equipment Design; D005080:Exercise Test / Q000379:methods; D064368:Healthy Volunteers; D018882:Heat Stress Disorders / Q000209:etiology / Q000517:prevention & control*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008834:Microclimate; D011481:Protective Clothing / Q000009:adverse effects*; D012881:Skin Temperature; D013546:Sweating; D013997:Time Factors; D014691:Ventilation / Q000295:instrumentation / Q000379:methods*
keywords: heat stress; microclimate cooling; protective clothing; sweat evaporation