Heat stress reduction of helicopter crew wearing a ventilated vest.

Abstract

BACKGROUND: Helicopter pilots are often exposed to periods of high heat strain, especially when wearing survival suits. Therefore, a prototype of a ventilated vest was evaluated on its capability to reduce the heat strain of helicopter pilots during a 2-h simulated flight. HYPOTHESIS: It was hypothesized that the ventilated vest would reduce pilot heat stress. METHODS: Five male and one female helicopter pilots flew for 2 h in a simulator in three different conditions; 15 degrees C wet bulb globe temperature (WBGT) without ventilation, 32 degrees C WBGT without ventilation, and 32 degrees C WBGT with a ventilated vest. RESULTS: Wearing the ventilated vest significantly reduced the increase in rectal temperature and increased thermal comfort. This made it possible for all subjects to complete the 2-h session. CONCLUSION: With the ventilated vest the subjects experienced less heat stress, thereby allowing all subjects to successfully complete the experiment, though two of the six pilots could not complete the 2-h flying task in the hot condition without cooling due to heat-related problems.