Effectiveness of ice-vest cooling in prolonging work tolerance time during heavy exercise in the heat for personnel wearing Canadian forces chemical defense ensembles
Effectiveness of a portable, ice-pack cooling vest (Steelevest) in prolonging work tolerance time in chemical defense clothing in the heat (33 C dry bulb, 33% relative humidity or 25 C WBGT) was evaluated while subjects exercised at a metabolic rate of approx. 700 watts. Subjects were six male volunteers. The protocol consisted of a 20 minute treadmill walk at 1.33 m/s. and 7.5% grade, followed by 15 minutes of a lifting task, 5 minutes rest, then another 20 minutes of lifting task for a total of one hour. The lifting task consisted of lifting of 20 kg box, carrying it 3 meters and setting it down. This was followed by a 6 m walk (3m back to the start point and 3 m back to the box) 15 sec after which the lifting cycle began again. The work was classified as heavy as previously defined. This protocol was repeated until the subjects were unable to continue or they reached a physiological endpoint. Time to voluntary cessation or physiological endpoint was called the work tolerance time. Physiological endpoints were rectal temperature of 39 C, heart rate exceeding 95% of maximum for two consecutive minutes or visible loss of motor control or nausea. The cooling vest had no effect on work tolerance time, rate of rise of rectal temperature or sweat loss. It was concluded that the Steelvest ice-vest is ineffective in prolonging work tolerance time and preventing increases in rectal temperature while wearing chemical protective clothing.
- Research Organization:
- Defence and Civil Inst. of Environmental Medicine, Downsview, ON (Canada)
- OSTI ID:
- 5459278
- Report Number(s):
- AD-A-235273/0/XAB
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL STRESS
BODY
BODY TEMPERATURE
CHEMICAL WARFARE
CLOTHING
CONTROL
COOLING
COOLING SYSTEMS
DIGESTIVE SYSTEM
ENERGY SYSTEMS
EXERCISE
GASTROINTESTINAL TRACT
ICE
INTESTINES
LARGE INTESTINE
LOSSES
MALES
METABOLISM
MILITARY PERSONNEL
MOTORS
NAUSEA
ORGANS
PERSONNEL
PROTECTIVE CLOTHING
RECTUM
SYMPTOMS
TOLERANCE
VISIBILITY
WARFARE