Physiological reactions of Caucasian and Bantu males in acute exposure to cold

1964 ◽  
Vol 19 (4) ◽  
pp. 583-592 ◽  
Author(s):  
C. H. Wyndham ◽  
J. S. Ward ◽  
N. B. Strydom ◽  
J. F. Morrison ◽  
C. G. Williams ◽  
...  
Keyword(s):  
Body Temperature ◽  
Ethnic Differences ◽  
Metabolic Response ◽  
Climatic Chamber ◽  
Air Temperatures ◽  
Metabolic Reactions ◽  
The Difference ◽  
Physiological Reactions ◽  
Average Skin ◽  
Skin Temperatures

Eleven men per sample of Caucasian and Bantu males were exposed for 2 hr in a climatic chamber at various air temperatures ranging from 5 to 27 C, and a wind velocity of 80–100 ft/min. When expressed per square meter surface area the metabolism of the Bantu was greater in the range above 18 C and below 6 C. Average skin temperatures were similar for both groups, but between 27 and 17 C the toe and finger temperatures of the Caucasians were significantly higher than that of the Bantu—the difference at 27 C being 5 C for the fingers and 3.6 C for the toes. Rectal temperatures of both groups were similar between 27 and 17 C. With the rectal temperatures at 27 C air temperature as the criterion, it was found that as the air temperatures decreased below the 27–17 C range the rectal temperatures of the Bantu fell linearly, while the rectal temperatures of the Caucasians rose steadily. There is no doubt that in certain ranges of air temperatures there are significant differences between the cold reactions of Caucasians and the Bantu. cold adaptation; ethnic differences in response to cold; metabolic and body temperature reactions to cold; metabolic response to body temperature; metabolic reactions of ethnic groups Submitted on July 15, 1963

Physiological reactions to cold of men in the Antarctic

1964 ◽  
Vol 19 (4) ◽  
pp. 593-597 ◽  
Author(s):  
C. H. Wyndham ◽  
R. Plotkin ◽  
A. Munro
Keyword(s):  
South African ◽  
Cold Adaptation ◽  
Physiological Responses ◽  
Control Group ◽  
Climatic Chamber ◽  
Thermoneutral Zone ◽  
The Antarctic ◽  
Physiological Reactions ◽  
Average Skin ◽  
Skin Temperatures

The physiological reactions to cold of five members of the 1961–1962 South African expedition to the Antarctic were studied in a climatic chamber in Johannesburg, and again after 6 months and after 12 months in the Antarctic. Their results were compared with the results of a control group in Johannesburg. The predeparture results were within the 95% significance intervals of the control group. After 12 months in the Antarctic their results fell outside the 95% significance intervals of the control group when at 5 C air temperature, metabolism, average skin temperatures, rectal temperatures, and finger temperatures were all significantly lower. Toe temperatures, however, were higher. There appeared to be a gradual “adaptation” and general “toughening” to the cold, because the subjects shed their clothing progressively until they could run about naked in the snow. The values at the thermoneutral zone of 27 C did not change over the 12 months, however. It is therefore concluded that it is unlikely that the changes in physiological responses were of endocrine origin. cold adaptation in Antarctic; metabolic and body temperature reactions to cold Submitted on August 16, 1963

Physiological reactions to cold of Bushmen, Bantu, and Caucasian males

1964 ◽  
Vol 19 (5) ◽  
pp. 868-876 ◽  
Author(s):  
C. H. Wyndham ◽  
J. F. Morrison ◽  
J. S. Ward ◽  
G. A. G. Bredell ◽  
M. J. E. Von Rahden ◽  
...  
Keyword(s):  
Heat Flow ◽  
Subcutaneous Tissue ◽  
Natural Habitat ◽  
Metabolic Rates ◽  
The Difference ◽  
Tissue Insulation ◽  
Physiological Reactions ◽  
Average Skin ◽  
Skin Temperatures ◽  
Made In

Two separate studies of the reactions to cold of one sample of 8 and one sample of 15 Kalahari Bushmen were made in their natural habitat and the results compared with the Bantu and, to a smaller extent, with the Caucasians. With a decrease in temperature from 27 to 5 C the metabolisms of all three groups rose. Metabolic rates per square meter of Bantu and Bushmen were similar, although higher than those of the Caucasians, but the percentage increases were closely similar for all groups. Rectal temperatures of Bushmen and Bantu were similar and decreased as the temperature dropped, while that of the Caucasians rose. Toe and finger temperatures of the Bushmen were higher over the whole temperature range than those of the Bantu and Caucasians, while the average skin temperatures were closely similar. Metabolic rates and rectal temperatures, therefore, indicate that subcutaneous tissue insulation against heat flow is greater for the Caucasians than for the Bantu or the Bushmen. Measurements of average skinfold thicknesses confirm this finding. Bushmen and Bantu reactions are quantitatively similar, but are qualitatively slightly different. From these findings we conclude that the difference between Bushmen, Bantu, and Caucasians is essentially morphological. desert and "river" Bushmen in the heat; effect of morphology on reaction to heat; heat reactions of Bantu and Bushmen; state of acclimatization to heat of Bushmen and Bantu; sweat rates of Bantu and Bushmen in standard heat conditions Submitted on October 21, 1963

Changes in body temperature and basal metabolic rate of the ama

1963 ◽  
Vol 18 (3) ◽  
pp. 483-488 ◽  
Author(s):  
B. S. Kang ◽  
S. H. Song ◽  
C. S. Suh ◽  
S. K. Hong
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Water Temperature ◽  
Basal Metabolic Rate ◽  
Cold Water ◽  
Four Seasons ◽  
Before And After ◽  
Average Skin ◽  
Skin Temperatures ◽  
Average Body

Oral temperatures of Korean diving women (ama) were measured before and after diving work in four seasons of the year. Their basal metabolic rate, measured in four seasons, was compared to that of nondiving women who lived in the same community and ate the same diet as the ama. Average oral temperatures declined to 35 C after 70 min of work in summer (water temp., 27 C) and to 33 C after 15 min of work in the winter (water temp., 10 C). Average body temperature, computed from weighted oral and average skin temperatures, declined to 34.6 C in summer and to 30 C in winter. Duration of work periods was determined principally by water temperature, since oral temperature declined at a rate inversely proportional to water temperature. The lower deep body temperatures which the ama endure in winter do, however, prolong their winter work period. The BMR of nondiving women was the same as the Dubois standard throughout the year. However, the BMR of ama varied with the season, ranging from +5 of the Dubois standard in summer to +35 in winter. We conclude that the elevated BMR of ama during the winter is cold adaptation, induced by repeated immersion in cold water. Submitted on November 23, 1962

Skin folds and Merino breeding. 6. The effects of varying heat exposures and degree of skin fold on rectal, scrotal, and testis temperatures

1968 ◽  
Vol 8 (31) ◽  
pp. 133 ◽  
Author(s):  
DG Fowler ◽  
JP Kennedy
Keyword(s):  
Body Temperature ◽  
Air Temperatures ◽  
Genetic Sampling ◽  
Skin Fold ◽  
Selection Experiments ◽  
Sampling Variation ◽  
The Difference ◽  
Thermoregulatory Function

During exposures of up to 12i hours duration at air temperatures of 30�C, 35�C, 40�C, and 45�C, Folds Minus rams maintained lower subcutaneous scrotal and intra-testicular temperatures than Folds Plus rams. This was observed with rams from two separately established skin fold selection experiments (Trangie and Cunnamulla). It therefore seems unlikely that the association between skin fold and the ability of rams to withstand heat is due to chance genetic sampling variation that might occur in small closed flocks of sheep. Cunnamulla Folds Plus and Folds Minus rams had similar rectal temperatures. Trangie Folds Plus rams had higher rectal temperatures than, those of Trangie Folds Minus rams but only at air temperatures of 30�C and 35�C. The differences in testicular temperature between the two types of rams are probably more dependant on differences in scrotal thermoregulatory function than on differences in body temperature. It has also been shown that the difference in scrotal thermoregulatory function for rams from the Trangie skin fold selection flocks is genetic in origin.

Physiological reactions to cold of Caucasian females

1964 ◽  
Vol 19 (5) ◽  
pp. 877-880 ◽  
Author(s):  
C. H. Wyndham ◽  
J. F. Morrison ◽  
C. G. Williams ◽  
G. A. G. Bredell ◽  
J. Peter ◽  
...  
Keyword(s):  
Air Temperature ◽  
Rectal Temperature ◽  
Metabolic Rates ◽  
Climatic Chamber ◽  
Finger Temperature ◽  
Air Temperatures ◽  
Applied Physiology ◽  
Cold Responses ◽  
Physiology Laboratory ◽  
Physiological Reactions

The physiological reactions to cold of nine female Caucasians were examined and compared with the reactions of a sample of male Caucasians. The experiment was conducted in the climatic chamber of the Applied Physiology Laboratory at air temperatures of 27 and 5 C, with a wind velocity of 80–100 ft/min. The sample of nine did not provide for intermediate temperature studies. The metabolic rates of the females were lower than those of the males, at both 27 and 5 C, but when expressed per square meter no differences were found. Finger and toe and rectal temperatures were the same for both sexes at 5 C, but the average female finger temperature was lower than that of the males at 27 C. The average female skin temperature was 2 C lower than that of the males. This indicates a greater subcutaneous insulation for females and this is confirmed by skinifold measurements. Both Caucasian sexes therefore display an increase in rectal temperature with fall in air temperature, which contrasts markedly with the Bantu and Bushman, both of whom show a decrease in rectal temperatures. Caucasian females and cold; cold responses of Caucasian females Submitted on September 17, 1963

Circadian variations in the sweating mechanism

1975 ◽  
Vol 39 (2) ◽  
pp. 226-230 ◽  
Author(s):  
J. Timbal ◽  
J. Colin ◽  
C. Boutelier
Keyword(s):  
Body Temperature ◽  
Human Subjects ◽  
Heat Exposure ◽  
The Body ◽  
Circadian Variations ◽  
Mean Body Temperature ◽  
Two Temperatures ◽  
The Difference ◽  
Gains And Losses ◽  
Skin Temperatures

Sweat rates and body temperatures of human subjects were measured at 0200, 1000, and 1800 h during a heat exposure of 90 min. The latent period of sweating was not significantly altered in the evening but significantly shortened during the night. Mean body temperature corresponding to the onset of sweating was nearer to the basal body temperature during the night, while during the day the difference between these two temperatures became larger. This phenomenon seems related to the circadian cycle of vasomotor adjustment, since during the night body conductance was higher than during the day and corresponded to a state of a vasodilatation similar to that observed at the onset of sweating. During the day, this situation was reversed. During steady state, the following changes were observed: sweating rate, night less than morning less than evening; skin temperatures, night less than morning less than evening; and rectal temperature increase, morning less than evening less than night. It is hypothesized that these changes are due to either different metabolic rates or an imbalance between heat gains and losses which preserve the circadian rhythm of the body temperature, even under thermal loads.

Evaluation of the accuracy of body temperature measurement using external radio transmitters

1996 ◽  
Vol 74 (9) ◽  
pp. 1778-1781 ◽  
Author(s):  
Doris Audet ◽  
Donald W. Thomas
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Field Conditions ◽  
Temperature Sensitive ◽  
External Temperature ◽  
Ambient Temperatures ◽  
Body Temperature Measurement ◽  
Radio Transmitters ◽  
The Difference ◽  
Skin Temperatures

The facultative depression of body temperature represents an important energy strategy for small homeotherms. However, measuring body temperature under field conditions by means other than externally attached temperature-sensitive radio transmitters is problematical. We show that skin temperatures measured by external radio transmitters can accurately reflect core temperature for the bat Carollia perspicillata. We compared body and skin temperatures at three ambient temperatures (Ta; 21, 26, and 31 °C). The difference between skin and body temperature (ΔT) was linearly correlated with Ta and can be predicted by ΔT = 4.396 − 0.118Ta. We argue that external temperature-sensitive radio transmitters can provide a reliable index of core temperature and so permit the study of torpor or facultative hypothermia under field conditions.

Respiratory metabolism studies on red-winged blackbird nestlings

1968 ◽  
Vol 46 (2) ◽  
pp. 223-233 ◽  
Author(s):  
M. I. Dyer
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Temperature Gradient ◽  
Respiratory Quotient ◽  
Environmental Temperature ◽  
Metabolic Response ◽  
Respiratory Metabolism ◽  
Nestling Period ◽  
Metabolic Reactions ◽  
Two Populations

Nestling red-winged blackbirds exhibited two distinct metabolic reactions to lowering temperatures. One group, which maintained homeothermic conditions, elevated its metabolism linearly according to a drop in ambient temperature and the second decreased its metabolic response in a curvilinear fashion. Core temperatures showed that although there was a progression toward the establishment of homeothermy throughout the nestling period, the birds could and did drop their core temperatures when the temperature gradient was too great to maintain constant body temperature. In some instances it is felt that oxygen consumption, and thus metabolism, was lowered before body temperature was suddenly dropped. No differences in the rates of metabolism could be found between upland and marshland populations; however, differences between values of the respiratory quotient for the two populations were found (p < 0.001). In addition differences in R.Q. values were found between well-developed nestlings practicing homeothermy and those that became hypothermic in response to lowering environmental temperature.

scholarly journals Method for evaluating the heat-island mitigation effect of porous/water-retentive blocks using a climatic chamber

2019 ◽  
Vol 80 (5) ◽  
pp. 855-863 ◽  
Author(s):  
Dae Uk Shin ◽  
Woo Bin Bae ◽  
Yun Mi Park ◽  
Sang Rae Kim ◽  
Yong Gil Kim
Keyword(s):  
Ambient Temperature ◽  
Temperature Measurements ◽  
Heat Island ◽  
Climatic Chamber ◽  
Environmental Chamber ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Circulation Mechanism ◽  
Design Requirements ◽  
The Difference

Abstract This paper presents a method and mock-up design for evaluating the heat-island mitigation effect of porous/water-retentive blocks in a climatic environmental chamber using ambient temperature measurements. To create the proposed method, the heat circulation mechanism of blocks was considered. From this, we specified the climatic chamber design requirements, determined the required components and equipment for the mock-up, and developed the proposed method for evaluating heat-island mitigation performance based on ambient temperature. Using the proposed mock-up design and method, we confirmed that both surface and air temperatures were lower when porous/water-retentive blocks were installed compared to conventional blocks. This method can be used to analyze the difference between surface and ambient temperatures under various conditions to quantify the heat-island mitigation performance of different materials according to ambient temperature.

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