Alterations in the Metabolic and Sympathetic Response to Cold Exposure after Cold Air Acclimation
Abstract
The armed services, primarily the Navy and Coast Guard, are tasked with maintaining free passage and security in many geographical locations encompassing tropical and polar conditions. While personnel performance in heat has been well studied and ameliorative guidelines implemented, little is known about performance and survival in the cold. Acute cold exposure elicits frank shivering concomitant with a short-term elevation in basal metabolism. Extended cold exposure can produced mild to severe hypothermia resulting in reduced cognitive function and manual dexterity, thus, having a tremendous effect on mental and physical performance. Moreover, personal safety and health can be compromised in such environments. The ability to adapt to these cold climates and possible improve one's performance has been extensively investigated. There is strong evidence that localized cold adaptation can occur over many years of exposure. Whether this adaptation is due to local factors, central factors, or both is not clear. The mechanism responsible for whole body cold adaptation is not clearly understood, but it is generally believed that various types of whole body cold adaptation are possible. Serum triiodothyronine (T3) is the primary hormone involved with many thermoregulatory and adaptive phenomena. As circulating T3 levels appear to be decreased with prolonged Antarctic residence, we sought to determine whether T3 supplementation and multiple cold air exposures would enhance human thermoregulation during a standardized cold air challenge.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 11, 1989
- Accession Number
- ADA216817
Entities
People
- D. W. Armstrong
- H. L. Reed
- K. Kowalski
- L. D. Allen
- R. L. Hesslink
Organizations
- Naval Medical Research Center