title: Ventilated vest and tolerance for intermittent exercise in hot, dry conditions with military clothing.
abstract: BACKGROUND
  Recent research has focused on developing air-ventilated garments to improve evaporative cooling in military settings. This study assessed a ventilated vest (Vest) in hot (45 degrees C), dry (10% RH) ambient conditions over 6 h of rest and exercise. It was hypothesized that the Vest would lower the thermal strain and increase the amount of exercise done by subjects.
  
  
  METHODS
  Eight healthy heat-acclimated men, wearing combat clothing, body armor, and a 19-kg load in webbing walked on a treadmill at 5 km h(-1) at a 2% incline until rectal temperature (T(rec)) reached 38.5 degrees C. They then rested until T(re) reached 38 degrees C, at which point they recommenced walking. On one occasion the subjects wore a Vest, blowing ambient air around the torso. On the second occasion subjects did not wear the vest (NoVest). Exercise/rest ratio, T(rec), skin temperature (T(sk)), sweat responses, rating of perceived exertion (RPE), and thermal comfort (TC) were measured.
  
  
  RESULTS
  Subjects wearing theVest exercised for significantly longer (18%; 11 min/h) as a percentage of total exposure time, stopped exercise significantly less often [Mean (SD); NoVest: 3 (2) stops; Vest: 1 (2) stops], and maintained significantly lower skin temperature under the body armor [T(chest): NoVest 37.55 (0.51) degrees C; Vest: 35.33 (1.00) degrees C; T(back): NoVest: 36.85 (0.83) degrees C; Vest: 35.84 (0.88) degrees C]. The Vest provided 28 W of cooling during exercise and 73 W when at rest as estimated by thermometry.
  
  
  CONCLUSIONS
  A ventilated vest can provide cooling, and thereby reduce thermal strain and increase exercise done in dry environmental temperatures up to 45 degrees C, without causing skin irritation and discomfort.
authors.affiliation: Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, Hampshire, UK. martin.barwood@port.ac.uk
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Barwood
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Newton
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Tipton
mesh_terms: D000293:Adolescent; D015331:Cohort Studies; D004867:Equipment Design; D005080:Exercise Test; D017079:Exercise Tolerance; D018882:Heat Stress Disorders / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008889:Military Personnel; D011481:Protective Clothing; D055815:Young Adult