Biomaterial Database

Response of prepubertal girls and college women to work in the heat. 1977

B L Drinkwater, and I C Kupprat, and J E Denton, and J L Crist, and S M Horvath

Five prepubertal females and five college women, matched for aerobic power, walked on a treadmill at approximately 30% VO2 max for two 50-min periods in three environments: 1) 28 degrees C, 45% rh, 2) 35 degrees C, 65% rh, and 3) 48 degrees C, 10% rh. In the mild heat (28 degrees C) both groups were able to work 100 min with no discomfort. At 35 and 48 degrees C tolerance time for the prepubertal subjects averaged 84.4 and 37.0 min, respectively; for adults, 100 and 75.0 min. At all temperatures the girls had higher heart rates and a lower stroke index, and finished the walks with a higher rectal temperature. There were no differences between groups in cardiac index, mean skin temperature, forearm blood flow, or percent loss in body weight. The proportion of the thermal load dissipated by the two groups was similar but the route for heat transfer was related to the BSA/wt ratio and environmental conditions. Marked circulatory instability was a primary factor in the lower tolerance of the prepubertal girls to work in the heat probably due to a shift in blood volume from the central to the peripheral circulation.

UI	MeSH Term	Description	Entries
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D011627	Puberty	A period in the human life in which the development of the hypothalamic-pituitary-gonadal system takes place and reaches full maturity. The onset of synchronized endocrine events in puberty lead to the capacity for reproduction (FERTILITY), development of secondary SEX CHARACTERISTICS, and other changes seen in ADOLESCENT DEVELOPMENT.	Puberties
D001830	Body Surface Area	The two dimensional measure of the outer layer of the body.	Area, Body Surface,Areas, Body Surface,Body Surface Areas,Surface Area, Body,Surface Areas, Body
D001833	Body Temperature Regulation	The processes of heating and cooling that an organism uses to control its temperature.	Heat Loss,Thermoregulation,Regulation, Body Temperature,Temperature Regulation, Body,Body Temperature Regulations,Heat Losses,Loss, Heat,Losses, Heat,Regulations, Body Temperature,Temperature Regulations, Body,Thermoregulations
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D005082	Physical Exertion	Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.	Physical Effort,Effort, Physical,Efforts, Physical,Exertion, Physical,Exertions, Physical,Physical Efforts,Physical Exertions
D005260	Female		Females
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic