Effect of cold exposure on various sites of core temperature measurements

1983 ◽  
Vol 54 (4) ◽  
pp. 1025-1031 ◽  
Author(s):  
S. D. Livingstone ◽  
J. Grayson ◽  
J. Frim ◽  
C. L. Allen ◽  
R. E. Limmer
Keyword(s):  
Gastrointestinal Tract ◽  
Metabolic Rate ◽  
Heat Production ◽  
Cold Exposure ◽  
Local Heat ◽  
Control Environment ◽  
Body Temperatures ◽  
Cold Stimulation ◽  
Facial Cooling ◽  
Internal Body

Rectal, esophageal, auditory canal, gastrointestinal tract, and sublingual temperature were recorded on five young Caucasian males who, in an environment of -32 degrees C and 11-km/h wind, sat during one 90-min exposure and walked on a treadmill at 2.9 km/h during another. The clothing permitted cooling of their torsos while giving adequate protection to their extremities. Control exposures involved subjects sitting in still air at 24–26 degrees C dressed only in thermal underwear. In the control environment all of the internal body temperatures measured gave comparable and consistent values; however, cold exposure affected the various sites differently. Esophageal temperatures fluctuated rapidly as a result of subjects swallowing cold saliva. Sublingual temperatures were below the lower limit of a clinical thermometer, possibly because of facial cooling. Auditory canal temperatures were low, perhaps also because of facial cooling. Rectal temperatures were high as were the gastrointestinal tract temperatures, due perhaps to local heat production in response to cold stimulation. Metabolic rate increased initially in the cold and again toward the end of the cold exposure.

Metabolic Factors in the Development of Homeothermy in Dogs

1958 ◽  
Vol 194 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Donald G. McIntyre ◽  
H. E. Ederstrom
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Metabolic Factors ◽  
Air Temperatures ◽  
Heat Conservation

Dogs from 1 to 25 days of age were exposed to air temperatures of 5, 23 and 30°C and their oxygen consumption measured in a closed calorimeter. Animals 1–5 days old had a rise of 20–25% in metabolic rate, but rectal temperature fell, when they were exposed to 5 or 23°C. At 11–21 days of age dogs exposed to 5°C had a rise of about 75% in metabolic rate, but rectal temperature fell several degrees in 1 hour. In dogs 21–25 days of age metabolic rate increased about 75% at air temperatures of 5°C and rectal temperature fell only about 1°C. Under the same conditions a trained adult dog had a rise of 80% in metabolic rate, and no fall in rectal temperature. Since heat production in 2- to 3-week-old dogs was increased to about the same extent as in the adult on cold exposure, it was assumed that heat conservation lagged behind heat production in the development of homeothermy.

Changing physiological relationships in men under acute cold stress

1970 ◽  
Vol 48 (1) ◽  
pp. 1-10 ◽  
Author(s):  
James F. O'Hanlon Jr. ◽  
Steven M. Horvath
Keyword(s):  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Heat Content ◽  
Body Temperatures ◽  
Older Subjects ◽  
Skin Temperatures ◽  
Different Levels ◽  
Body Heat ◽  
Thigh Temperature

Thirty-four men were exposed to 8 °C for 2 h. Their reactions were studied to indicate how physiological relationships change during exposure to cold. Measurements of various body temperatures, MST, MBT, body heat content (BHC), [Formula: see text], heat production, and heart rate (HR) were made before the onset of and periodically during cold exposure. Various skin temperatures fell to different levels while rectal temperature rose slightly, then fell 0.3 °C by the end of the exposure. BHC declined by 6%, [Formula: see text] nearly doubled, [Formula: see text] and heat production increased by 66 and 75% respectively, and HR changed little during cold exposure. Relationships which changed most significantly during cold exposure were those between MST and rectal temperature, certain skin temperatures and rectal temperature, [Formula: see text] (also heat production) and BHC, [Formula: see text] and rectal temperature, and finally, those between every body temperature and the age of the subjects. Relationships which also changed were those between finger and toe temperature as well as those between [Formula: see text] (also heat production) and each of the following: [Formula: see text], rectal temperature, thigh temperature, HR, and age. These results indicated that (1) temperature in the upper extremities was actively maintained at a higher level than temperature in the lower extremities, (2) increased metabolism became a progressively more effective adaptation than redistribution of blood volume, (3) subjects with the lowest BHC tended to increase their metabolism the most, (4) [Formula: see text] was inversely related to core temperature after the latter fell below normal, (5) HR was unrelated to the increase in [Formula: see text], (6) the usual inverse relationship between age and metabolism was not found in the cold, and finally, (7) older subjects generally tended to maintain higher body temperatures than younger subjects.

Effect of aminophylline on metabolic and thermoregulatory responses during hypothermia associated with cold exposure in lambs

2003 ◽  
Vol 83 (4) ◽  
pp. 739-748 ◽  
Author(s):  
B. Zimmermann ◽  
G. Diebold ◽  
J. Galbraith ◽  
W. Whitmore ◽  
M. Okamoto ◽  
...  
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Phosphodiesterase Inhibitor ◽  
Rate Of Development ◽  
Dose Rates ◽  
Maximum Metabolic Rate ◽  
Response Trial

Three experiments were conducted with lambs to test the hypothesis that the phosphodiesterase inhibitor/adenosine blocker, aminophylline would enhance metabolic rate and delay the development of hypothermia. In exp. 1, eight lambs were treated either with aminophylline or control (0.9% saline) injections. During hypothermia, metabolic rate was increased from a resting value of 4.8 W kg-1 to maximum values of 15–16 W kg-1. The rate of development of hypothermia and recovery there from were inversely related to age and body weight. Aminophylline (8 mg kg-1) did not affect resting or maximum metabolic rate, but after a second injection, aminophylline increased metabolic rate after warming (P < 0.05) and tended to shorten the absolute period of time to restore normal rectal temperature (P < 0.10). In exp. 2, a dose-response trial with six lambs each receiving 0, 2, 16 or 32 mg aminophylline indicated that dose rates of 16 and 32 mg kg-1 increased (P < 0.05) metabolic rate of lambs. In exp. 3, 21 lambs received either 0.9% saline or aminophylline (24 mg kg-1) injections. Mean heat production ranged from 13 to 15 W kg-1 and was increased approximately 7% (P < 0.01) by aminophylline. Aminophylline, therefore, has some potential as a treatment for hypothermia or to improve recovery from hypothermia in lambs by increasing metabolic rate during cold stress. Key words: Lamb, metabolic rate, hypothermia, thermoregulation, Aminophylline®, phosphodiesterase inhibitor

Mechanisms of cold acclimatization in the cat

1963 ◽  
Vol 18 (4) ◽  
pp. 778-780 ◽  
Author(s):  
Thomas Adams
Keyword(s):  
Cold Exposure ◽  
Whole Body ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Peripheral Vascular ◽  
Air Exposure ◽  
Cold Acclimatization ◽  
Tissue Insulation ◽  
Body Heat ◽  
Internal Body

Thermoregulatory control in cats living at 25 C was compared to the regulation of body temperature in the same species after continuous whole-body cold exposure to an ambient temperature of 5 C for periods exceeding 2 months. Rectal and extremity temperatures and metabolic rates for the two groups were examined during acute (2-hr) air exposures to 23, 10, and 0 C. Cold acclimatizing mechanisms in the cat involve a redistribution of body heat at 23 C, obligating increased heat flux at the expense of elevated metabolism, an improved peripheral vascular defense (increase functional tissue insulation) during moderate cold exposure (10 C), and a greater ability to increase heat production accompanied by more labile peripheral vasomotion, during more severe cold air exposure (0 C). Although resting at 23 C, cold-acclimatized cats had lower rectal temperatures and were able to maintain higher internal body temperatures during both levels of cold stress compared to noncold-acclimatized animals. Submitted on November 1, 1962

Thermoregulatory and metabolic changes during fever in young and old rats

2003 ◽  
Vol 285 (5) ◽  
pp. R1165-R1169 ◽  
Author(s):  
Jessica B. Buchanan ◽  
Elizabeth Peloso ◽  
Evelyn Satinoff
Keyword(s):  
Metabolic Rate ◽  
Heat Loss ◽  
Heat Production ◽  
Metabolic Changes ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Young Rats ◽  
Heat Conservation ◽  
Old Rats ◽  
S Peak

We injected old and young rats with lipopolysaccharide (LPS; 50 μg/kg ip) at two ambient temperatures ( Ta; 21 and 31°C). Young rats mounted equivalent fevers at both Tas [peak body temperatures ( Tb) of 38.3 and 38.7°C, respectively]. The Tbof old rats was not different from baseline (37.3°C) after LPS at Ta21°C, whereas, at 31°C, their Tbrose to a mean peak of 38.4°C. We also measured the associated thermoregulatory responses by use of calorimetry. At 21°C, young rats developed a fever by increasing both O2consumption and heat conservation. Old rats did not become febrile, and O2consumption fell by 15%. Heat loss was the same in old and young rats. At 31°C, young and old rats developed similar fevers with similar increases in heat production and conservation. Our results suggest that the lack of LPS fever in old rats at 21°C is due mainly to the lowered metabolic rate.

scholarly journals Cold-induced heat production preceding shivering

2005 ◽  
Vol 93 (3) ◽  
pp. 387-391 ◽  
Author(s):  
Anne M. J. van Ooijen ◽  
Wouter D. van Marken Lichtenbelt ◽  
Anton A. van Steenhoven ◽  
Klaas R. Westerterp
Keyword(s):  
Body Composition ◽  
Body Temperature ◽  
Skin Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Normal Weight ◽  
Test Period ◽  
Body Temperatures ◽  
Large Heat

Individual changes in heat production and body temperature were studied in response to cold exposure, prior to shivering. The subjects ten women (seven men) were of normal weight, had a mean age of 23 (SD 3) years and average BMI 22·2 (SD 1·6) Kg/m2. They were lying supine under thermoneutral conditions for 30 min and were subsequently exposed to air of 15°C until shivering occurred. Heat production was measured with a ventilated hood. Body composition was measured with underwater weighing and 2H dilution. Body temperatures were measured with thermistors. Heat production during cold exposure prior to shivering increased and reached a plateau. Skin temperature decreased and did not reach a plateau during the test period. The non-shivering interval (NSI) ranged from 20 to 148 min, was not related to body composition and was not significantly different between women (81 (sd 15) min) and men (84 (sd 34) min). NSI was negatively related to skin temperature (r2 0·44, P=0·004), and skin temperature was related to heat production (r2 0·39, P=0·007) In conclusion, subjects with a relatively large heat production during cold exposure maintained a relatively high skin temperature but showed a short NSI, independent of differences in body composition.

Thermal and metabolic responses of the Australian aborigine exposed to moderate cold in summer

1959 ◽  
Vol 14 (4) ◽  
pp. 605-615 ◽  
Author(s):  
H. T. Hammel ◽  
R. W. Elsner ◽  
D. H. Le Messurier ◽  
H. T. Andersen ◽  
F. A. Milan
Keyword(s):  
Metabolic Rate ◽  
Cold Exposure ◽  
Prolonged Exposure ◽  
Metabolic Responses ◽  
Body Temperatures ◽  
Australian Aborigines ◽  
Metabolic Compensation ◽  
Australian Aborigine ◽  
Body Cooling ◽  
And Control

Measurements of thermal and metabolic responses of central Australian aborigines exposed to moderate cold during sleep were repeated during summer and have shown that the small, but important, differences between these natives and control whites exist in summer to the same extent as in winter. The metabolism of the central natives declined continually throughout the night with a Q10 of about two in summer as in winter. Without metabolic compensation, body temperatures of the central natives fell at a greater rate than those of the whites. Measurements of thermal and metabolic responses of a mixed tribal group of tropical Australian aborigines under identical conditions of cold exposure have shown that the average tropical native was intermediate between central natives and control whites. The metabolic rate for tropical natives was 42.8 Cal/m2/hr. compared with 48.7 Cal/m2/hr. for whites and 37.0 Cal/m2/hr. for central natives. We suggest that the Australian aborigine has an inborn ability to tolerate greater body cooling without metabolic compensation which can be increased by prolonged exposure to cold. Submitted on December 3, 1958

scholarly journals Exercise-Generated Heat Contributes to Thermoregulation by Gambel's Quail in the Cold

1992 ◽  
Vol 171 (1) ◽  
pp. 409-422 ◽  
Author(s):  
EILEEN ZERBA ◽  
GLENN E. WALSBERG
Keyword(s):  
Oxygen Consumption ◽  
Heat Production ◽  
Cold Exposure ◽  
Metabolic Heat Production ◽  
Energetic Cost ◽  
Convective Conditions ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Metabolic Heat ◽  
Gambel's Quail

The purpose of this study was to investigate the relationship between the allocation of exercise-generated heat and resting metabolic heat production during cold exposure. We tested the hypothesis that, during cold exposure, exercise-generated heat contributes to the fulfillment of the thermostatic requirement. Our assumption was that the thermostatic requirement is higher for exercising than for resting birds in still air because of the disruption of boundary and plumage insulation layers. We predicted that, during moderate exercise, the metabolic heat production of exercising birds would be higher than that for resting birds in still air but would not differ significantly from the metabolic heat generated by resting birds exposed to similar convective conditions. To test our hypothesis we measured whole-animal oxygen consumption of Gambel's quail (Callipepla gambelii Gambel) running in a circular metabolic chamber and at rest in still air at ambient temperatures below the animal's lower critical temperature. We compared these data to previous data for Gambel's quail at rest exposed to wind at a speed equal to the running speed used in our experiments. In addition to oxygen consumption measurements, we measured body temperatures of exercising and resting birds. The data supported our assumption and predictions. (1) Whole-body thermal resistance for exercising birds was lower than that for resting birds in still air, indicating that the thermostatic requirement was higher for exercising birds because of the disruption of boundary and plumage insulation layers. (2) Heat productions of exercising birds were significantly higher than those of resting birds in still air but were not significantly different from the heat productions of resting birds exposed to similar convective conditions. (3) Body temperatures were not significantly different between resting birds in still air and exercising birds. The mean body temperature of exercising birds, however, was 2°C higher than that of resting birds exposed to wind. We concluded that an exercising animal probably does not incur an energetic cost associated with locomotor activity at low ambient temperatures in comparison to an inactive animal exposed to a similar convective regime. Note: Present address: Department of Biology, University of Michigan, Ann Arbor, MI 48109–1048, USA.

scholarly journals Cold-induction of afadin in brown fat supports its thermogenic capacity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Morten Lundh ◽  
Ali Altıntaş ◽  
Marco Tozzi ◽  
Odile Fabre ◽  
Tao Ma ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Functional Enrichment ◽  
Activation Process ◽  
Target Tissue ◽  
Cold Stimulation ◽  
Brown Adipocytes ◽  
Protein Levels ◽  
Mrna Induction ◽  
Metabolic Functions ◽  
Brown Adipose

AbstractThe profound energy-expending nature of brown adipose tissue (BAT) thermogenesis makes it an attractive target tissue to combat obesity-associated metabolic disorders. While cold exposure is the strongest inducer of BAT activity, the temporal mechanisms tuning BAT adaptation during this activation process are incompletely understood. Here we show that the scaffold protein Afadin is dynamically regulated by cold in BAT, and participates in cold acclimation. Cold exposure acutely increases Afadin protein levels and its phosphorylation in BAT. Knockdown of Afadin in brown pre-adipocytes does not alter adipogenesis but restricts β3-adrenegic induction of thermogenic genes expression and HSL phosphorylation in mature brown adipocytes. Consistent with a defect in thermogenesis, an impaired cold tolerance was observed in fat-specific Afadin knockout mice. However, while Afadin depletion led to reduced Ucp1 mRNA induction by cold, stimulation of Ucp1 protein was conserved. Transcriptomic analysis revealed that fat-specific ablation of Afadin led to decreased functional enrichment of gene sets controlling essential metabolic functions at thermoneutrality in BAT, whereas it led to an altered reprogramming in response to cold, with enhanced enrichment of different pathways related to metabolism and remodeling. Collectively, we demonstrate a role for Afadin in supporting the adrenergic response in brown adipocytes and BAT function.

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Elevated Serum ◽  
Body Temperatures ◽  
Serum Thyroid Hormone ◽  
Regulate Body Temperature ◽  
Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

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