Effects of Serial Wet-Dry-Wet Cold Exposure: Thermal Balance, Physical Activity, and Cognitive Performance.

摘要

Thermal balance, physical performance, and cognitive function were examined in 7 U.S. Navy divers who each performed two 7-hour cold exposures while wearing a TLS dry suit with M-400 Thinsulate insulation for thermal protection. The exposures consisted of 2.5 h immersed in 5 C water, followed by 2 h in 5 C air, and then reentering the water for another 2.5 h. This exposure paradigm was intended to simulate an operational mission involving a wet-dry-wet cold exposure. During each exposure, leg exercise at 50 W was performed for the last 30 min of the first immersion and the first 30 min of the second immersion. In the course of one cold exposure, the subject walked 90 min on a treadmill at 2 mph during the dry phase, while during the other exposure he remained seated at rest for the dry phase. Cognitive function, measured at rest during the midpoint of each dry phase, was assessed by a battery of 7 NMRI-PAB tests. Keywords: Performance human; Heat stress; Diving; Thermal protection; Environmental stress; Exercise; Hydration; Cognitive performance. (KT)