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.

Effects of oral glycine during cold exposure in man

1959 ◽  
Vol 14 (3) ◽  
pp. 390-392 ◽  
Author(s):  
William R. Beavers ◽  
Benjamin G. Covino
Keyword(s):  
Oxygen Consumption ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Human Subjects ◽  
Exposure Period ◽  
Blood Flows ◽  
Skin Temperatures ◽  
Warm Room

Six male human subjects were given 30 gm oral glycine. Oxygen consumption, skin and rectal temperatures, and forefinger blood flows were measured during an interval in a warm room and then during 75 minutes cold exposure (0°F). The same subjects receiving 30 gm glucose served as controls. Glycine increased heat production at rest in a warm room and also during cold exposure. The subjects when receiving glycine had a slightly higher rectal temperature and higher skin temperatures in areas other than fingers during the cold exposure period. Submitted on August 1, 1958

Effect of continuous cold exposure on nocturnal body temperatures of man

1959 ◽  
Vol 14 (1) ◽  
pp. 43-45 ◽  
Author(s):  
M. B. Kreider ◽  
P. F. Iampietro ◽  
E. R. Buskirk ◽  
David E. Bass
Keyword(s):  
Body Temperature ◽  
Cold Stress ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Control Period ◽  
Cold Period ◽  
Body Temperatures ◽  
Temperature Responses

Effects of continuous cold stress on 24-hour patterns of body temperature were studied in five men. Cold stress consisted in living at 15.6℃ (60℉) for 14 days wearing only shorts. The cold period was preceded and followed by 2 weeks at 26.7℃ (80℉). Activity (minimal) and diet were the same for all periods. One blanket was used at night. Rectal temperature (Tr) and skin temperature (Ts) were measured. Tr during sleep fell more rapidly and to lower values during cold exposure (35.6℃) than during the control period (36.1℃). Ts during sleep was slightly lower in the cold than in the control period; also, Ts did not exhibit the gradual drop characteristic of sleep in the control period. Comparison of Tr and Ts between early and later cold days revealed the following differences: a) nocturnal Tr fell to lower levels on the later cold days; b) nocturnal toe temperatures were 15℃ (27℉) higher on the later cold days. The arch temperatures followed the same pattern as the toes. No significant differences were found in daytime temperatures between early and later cold days. The data suggest that evidence for acclimatization to cold in terms of altered body temperature responses may be fruitfully sought in responses during rewarming and/or sleep. Submitted on September 19, 1958

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.

Metabolic and thermal responses of women during cooling in water

1974 ◽  
Vol 36 (5) ◽  
pp. 577-580 ◽  
Author(s):  
J. Kollias ◽  
L. Barlett ◽  
V. Bergsteinova ◽  
J. S. Skinner ◽  
E. R. Buskirk ◽  
...  
Keyword(s):  
Body Fat ◽  
Young Women ◽  
Heat Production ◽  
Cold Exposure ◽  
Korean Women ◽  
Mass Ratio ◽  
Body Fatness ◽  
Body Fat Content ◽  
Tissue Insulation ◽  
Skin Temperatures

The metabolic and thermal responses of 10 young women, 3 lean (21–24% fat) and 7 obese (29–41% fat), were measured during head-out immersion in a stirred water bath maintained at 20°C. Continuous measurements of heat production (M), rectal (Tre, esophageal (Tes), and skin temperatures were obtained. The rate and magnitude of the increase in M and decrease in core temperatures were significantly greater in the lean than the obese group. Tissue insulation values for lean women were similar to those reported for diving and nondiving Korean women in 30°C water. Lean women with 22% body fat have a larger SA/mass ratio than men of comparable body fat content and cool at a greater rate. It is concluded that SA/mass as well as body fatness and size must be considered in the overall metabolic and thermal responses to cold exposure.

Relation of changing levels of physical fitness to human cold acclimatization

1961 ◽  
Vol 16 (2) ◽  
pp. 226-230 ◽  
Author(s):  
Earl J. Heberling ◽  
Thomas Adams
Keyword(s):  
Physical Activity ◽  
Cold Exposure ◽  
Physical Training ◽  
Normal Activity ◽  
Body Temperatures ◽  
Cold Acclimatization ◽  
Caucasian Men ◽  
Cold Chamber ◽  
Skin Temperatures ◽  
Trunk Skin

Five nude Caucasian men were exposed for 1 hour to a temperature of 10° α 1°C in a cold chamber after normal activity, after physical training, and after bivouac in the interior of Alaska for 6 weeks during January and February. Body temperatures (hand, foot, trunk, skin, and rectal, recorded during exposure to acute cold, were the criteria by which the effects of the changing levels of physical training and the cold-acclimatizing encampment were compared and judged. After the program of physical training, but before the bivouac, skin and extremity temperatures were statistically higher than those recorded before training; no differences were noted after the bivouac, when the level of physical training remained unchanged and the only variable was exposure to cold. These data confirm an earlier suggestion that commonly accepted indices of acclimatization, (elevated skin temperatures) may also result from chronically elevated levels of physical activity. Additional evidence indicates the limitations of the bivouac or field exercises for 'cold exposure,' and suggests the questionable value of accepting physiological and thermal readjustments that occur during such programs as being indicative of the effects of cold. Submitted on July 5, 1960

Circadian rhythm of heat production, heart rate, and skin and core temperature under unmasking conditions in men

1994 ◽  
Vol 267 (3) ◽  
pp. R819-R829 ◽  
Author(s):  
K. Krauchi ◽  
A. Wirz-Justice
Keyword(s):  
Heart Rate ◽  
Circadian Rhythm ◽  
Heat Loss ◽  
Rectal Temperature ◽  
Heat Production ◽  
Circadian Variation ◽  
Bed Rest ◽  
Sodium Potassium ◽  
Hands And Feet ◽  
Skin Temperatures

Seven healthy men were studied in a 34-h constant routine protocol to investigate whether the daily rhythm of heat production and heat loss has an endogenous circadian component. Under these unmasking conditions (constant bed rest, no sleep allowed, regular food and fluid intake), a significant circadian rhythm could be demonstrated for heat production, heart rate, and skin temperatures but not for the respiratory quotient. Heat production and heart rate were phase locked with a maximum at 1100-1200 h. Proximal skin temperatures (infraclavicular region, thigh, and forehead) followed the same circadian rhythm as rectal temperature, whereas distal skin temperatures (hands and feet) were opposite in phase. These physiological circadian rhythm parameters, as well as biochemical parameters (urinary sodium, potassium, urea, and urine flow), were phase advanced by 25-180 min with respect to the circadian rhythm in rectal temperature. Our findings under unmasking conditions show that the circadian variation in rectal temperature is a consequence of endogenous circadian rhythms in both heat production and heat loss.

Observations on the effect of salicylate in fever and the regulation of body temperature against cold

1976 ◽  
Vol 54 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Q. J. Pittman ◽  
W. L. Veale ◽  
K. E. Cooper
Keyword(s):  
Body Temperature ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Intravenous Infusion ◽  
Sodium Salicylate ◽  
Single Injection ◽  
Continuous Intravenous Infusion ◽  
Skin Temperatures

Prostaglandins appear to be mediators, within the hypothalamus, of heat production and conservation during fever. We have investigated a possible role of prostaglandins in the nonfebrile rabbit during thermoregulation in the cold. Shorn rabbits were placed in an environment of 20 °C, and rectal and ear skin temperatures, shivering and respiratory rates were measured. A continuous intravenous infusion of leucocyte pyrogen was given to establish a constant fever of approximately 1 °C, and after observation of a stable febrile temperature for 90 min, a single injection of 300 mg of sodium salicylate, followed by a 1.5 mg/min infusion was then given. After the salicylate infusion was begun, rectal temperature began to fall, and reached nonfebrile levels within 90 min. Shivering activity ceased, respiratory rates increased, and in two animals, ear skin temperature increased. When these same rabbits were placed in an environment of 10 °C, at a time they were not febrile, and an identical amount of salicylate was given, rectal and ear skin temperatures, shivering and respiratory rates did not change. These results indicate that prostaglandins do not appear to be involved in heat production and conservation in the nonfebrile rabbit.

Thermoregulation during cold exposure after several days of exhaustive exercise

2001 ◽  
Vol 90 (3) ◽  
pp. 939-946 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
David W. Degroot ◽  
Dean A. Stulz ◽  
Bruce S. Cadarette ◽  
...  
Keyword(s):  
Rectal Temperature ◽  
Cold Exposure ◽  
Physical Exertion ◽  
Exhaustive Exercise ◽  
Mean Skin Temperature ◽  
Metabolic Heat ◽  
Fatiguing Exercise ◽  
Water Saturated ◽  
Skin Temperatures ◽  
Experimental Group

This study examined the hypothesis that several days of exhaustive exercise would impair thermoregulatory effector responses to cold exposure, leading to an accentuated core temperature reduction compared with exposure of the same individual to cold in a rested condition. Thirteen men (10 experimental and 3 control) performed a cold-wet walk (CW) for up to 6 h (6 rest-work cycles, each 1 h in duration) in 5°C air on three occasions. One cycle of CW consisted of 10 min of standing in the rain (5.4 cm/h) followed by 45 min of walking (1.34 m/s, 5.4 m/s wind). Clothing was water saturated at the start of each walking period (0.75 clo vs. 1.1 clo when dry). The initial CW trial ( day 0) was performed (afternoon) with subjects rested before initiation of exercise-cold exposure. During the next 7 days, exhaustive exercise (aerobic, anaerobic, resistive) was performed for 4 h each morning. Two subsequent CW trials were performed on the afternoon of days 3 and 7, ∼2.5 h after cessation of fatiguing exercise. For controls, no exhaustive exercise was performed on any day. Thermoregulatory responses and body temperature during CW were not different on days 0, 3, and 7 in the controls. In the experimental group, mean skin temperature was higher ( P< 0.05) during CW on days 3 and 7 than on day 0. Rectal temperature was lower ( P < 0.05) and the change in rectal temperature was greater ( P < 0.05) during the 6th h of CW on day 3. Metabolic heat production during CW was similar among trials. Warmer skin temperatures during CW after days 3 and 7indicate that vasoconstrictor responses to cold, but not shivering responses, are impaired after multiple days of severe physical exertion. These findings suggest that susceptibility to hypothermia is increased by exertional fatigue.

Variation in the responses of shorn sheep to cold exposure

1966 ◽  
Vol 8 (3) ◽  
pp. 425-434 ◽  
Author(s):  
J. Slee
Keyword(s):  
Cold Tolerance ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Cold Treatment ◽  
Subcutaneous Fat ◽  
Previous History ◽  
Live Weight ◽  
Late Pregnancy ◽  
Gestation Length ◽  
Skin Temperatures

Thirteen Blackface and Merino × Cheviot female sheep were shorn and each exposed for a maximum of 10 hours to intense cold (—18° C, 4 m.p.h. wind). Individual exposures were terminated earlier if rectal temperatures fell by 4·5° C. In the first year of the experiment (1963) 11 out of 13 of the sheep were in late pregnancy. There were also 12 control sheep, 9 of them pregnant, which were not subjected to cold treatment. In 1964, 12 of the previously treated sheep were subjected again to similar cold exposures. This time they were unmated and there were no controls.The cold treatment apparently caused increased variation in gestation length, but the effects on neo-natal lamb mortality were inconclusive.In 1963 and 1964 there was wide variation between individual sheep in cold tolerance—defined as the ability to maintain rectal temperature during cold exposure. Repeatability for this character was approximately 0·73, suggesting the existence of a genetic component. The average decline in rectal temperature was similar in both years: 3·9·2° C. in 1964. Pregnancy and breed had no detectable effects on cold tolerance.Skin temperatures on the midside, ear and hind foot (pastern) were measured in 1964. They all declined during cold exposure. Midside skin temperatures typically fell to about 10° C., ear temperatures to about 3° C. and foot temperatures to zero. There were temperature fluctuations due to periodic vasodilation on the ears but the feet generally showed sustained vasoconstriction.Superior cold tolerance tended to be associated with low mean body skin temperatures and a previous history of live-weight gain. It is suggested that subcutaneous fat deposition may be one factor responsible for improving skin insulation and thereby reducing heat loss in shorn sheep, but direct evidence for this was lacking.

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