Accession Number : AD0690089

Title :   A COMPARATIVE STUDY OF THE EFFECT ON MEN OF CONTINUOUS VERSUS INTERMITTENT EXPOSURE TO A TROPICAL ENVIRONMENT,

Corporate Author : NAVAL MEDICAL RESEARCH INST BETHESDA MD

Personal Author(s) : Pace,Nello ; Fisher,M. B. ; Birren,J. E. ; Pitts,Grover C. ; White,W. A. , Jr

Report Date : 09 MAY 1945

Pagination or Media Count : 34

Abstract : Two groups of six men each lived in a temperature environment of approximately 85F for nine hours daily. One group remained at this temperature for twelve hours at night. The intermittent exposure group, was removed to an 'effective temperature' of approximately 75F during the twelve hours at night. Both groups spent the three hours remaining in each day at an 'effective temperature' of approximately 90F during which time they performed treadmill work tests. The men were exposed to these conditions for thirty days. The period of heat was preceded by a control period of eight days and was followed by a recovery period of six days. During these periods both groups lived continuously in an ambient 'effective temperature' of approximately 75F. Physiologial and psychological test batteries were administered daily to the two groups, and a clinical examination was conducted three times a week. The hot group exhibited extensive heat rash which continued throughout the thirty-day period, whereas the cool group experienced nearly complete freedom from heat rash. The mean basal rectal temperature of the hot group was approximately one degree F higher than that of the cool group. The mean basal pulse rate was about four beats higher than that of the cool group. The water loss during the night was approximately double that of the cool group. The cool group showed greater ease of going to sleep, more spontaneous activity, and greater alertness. None of the sensorimotor functions tested and only a few of the physiological measures showed a difference between the two groups.

Descriptors :   (*TROPICAL REGIONS, EXPOSURE(PHYSIOLOGY)), (*HEAT TOLERANCE, TROPICAL REGIONS), HUMIDITY, SKIN(ANATOMY), DISEASES, HUMAN BODY, DIET, HEAT, ENDURANCE(PHYSIOLOGY), PERFORMANCE(HUMAN), PATHOLOGY, RESPONSE(BIOLOGY), DEGRADATION

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE