The Effect of Hypoxia, Cold, and Exercise on Human Thermoregulation.
Abstract
U.S. Marine and Navy personnel may be at an increased risk for developing hypothermia when training at 2700 m. The objective of this study was to determine if exposure to moderate cold and decreased oxygen (O2) tension (15% O2 simulating 2700 m) reduces the ability of the human body to shiver and to maintain core and skin temperatures during moderate exercise. Eight male and two female U.S. Navy and Marine Corps personnel participated as subjects. Subjects were exposed to 4.4 deg C air breathing either 20.9% O2 (N) or 15% O2 (H) for 120 min, 40 min sitting, then 40 min walking on a treadmill at 3.0 mph, then sitting for 40 min. All subjects shivered vigorously during N and H cold as observed by investigators, reported in thermal sensation, and measured by electromyograms. The exposure of H does not decrease the ability of the human body to shiver. The respiratory exchange ratio did increase with H, indicating an increased need for glucose, and H decreased the O2 blood saturation, indicating less O2 is being carried in the blood, resulting in a possible limitation in maximal aerobic capacity. Therefore, thermoregulation during military missions conducted at altitudes up to 2700 m should not be affected adversely by the reduction in inspired O2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 23, 1996
- Accession Number
- ADA323293
Entities
People
- David Roberts
- J. Hodgdon
- J. Reading
- R. Pozos
Organizations
- Naval Health Research Center