Effects of fitness, fatness, and age on men's responses to whole body cooling in air

1991 ◽  
Vol 71 (6) ◽  
pp. 2387-2393 ◽  
Author(s):  
G. M. Budd ◽  
J. R. Brotherhood ◽  
A. L. Hendrie ◽  
S. E. Jeffery
Keyword(s):  
Multiple Regression ◽  
Skinfold Thickness ◽  
Fat Free Mass ◽  
Whole Body ◽  
Skin Fold Thickness ◽  
Skin Fold ◽  
Vasoconstrictor Response ◽  
Tissue Insulation ◽  
Body Cooling ◽  
Whole Body Cooling

Simple and multiple regression analyses were used to assess the influence of 12 white men's fitness (aerobic capacity 44–58 ml O2.min-1.kg fat-free mass-1), fatness (mean skin-fold thickness 5–20 mm, body fat content 15–36%), and age (26–52 yr) on their thermal, metabolic, cardiovascular, and subjective responses to 2 h of whole body cooling, nude, in air at 10 degrees C. Fitter men had slower heart rates, and fatter men had higher blood pressures. Fitness had no effect (P greater than 0.39) on any measured response to cold. Fatness was associated (P less than 0.01) with reduced heat loss, heat production, and mean skin temperature; unchanged heat debt; and increased tissue insulation. Age had the opposite effects. When the confounding effects of fatness were held constant by multiple regression, older men responded to cold as though they were 1 mm of skinfold thickness leaner for each 3–4 yr of age. We conclude that aging, even between the relatively youthful ages of 26 and 52 yr, is accompanied by a progressive weakening of the vasoconstrictor response to cold.

The role of baseline in the cutaneous vasoconstrictor responses during combined local and whole body cooling in humans

2007 ◽  
Vol 293 (5) ◽  
pp. H3187-H3192 ◽  
Author(s):  
Gary J. Hodges ◽  
Wojciech A. Kosiba ◽  
Kun Zhao ◽  
Guy E. Alvarez ◽  
John M. Johnson
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Local Heating ◽  
Laser Doppler ◽  
Whole Body ◽  
Local Cooling ◽  
Doppler Flowmetry ◽  
Vasoconstrictor Response ◽  
Body Cooling ◽  
Whole Body Cooling

Previous work showed that local cooling (LC) attenuates the vasoconstrictor response to whole body cooling (WBC). We tested the extent to which this attenuation was due to the decreased baseline skin blood flow following LC. In eight subjects, skin blood flow was assessed using laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was expressed as LDF divided by blood pressure. Subjects were dressed in water-perfused suits to control WBC. Four forearm sites were prepared with microdialysis fibers, local heating/cooling probe holders, and laser-Doppler probes. Three sites were locally cooled from 34 to 28°C, reducing CVC to 45.9 ± 3.9, 42 ± 3.9, and 44.5 ± 4.8% of baseline ( P < 0.05 vs. baseline; P > 0.05 among sites). At two sites, CVC was restored to precooling baseline levels with sodium nitroprusside (SNP) or isoproterenol (Iso), increasing CVC to 106.4 ± 12.4 and 98.9 ± 10.1% of baseline, respectively ( P > 0.05 vs. precooling). Whole body skin temperature, apart from the area of blood flow measurement, was reduced from 34 to 31°C. Relative to the original baseline, CVC decreased ( P < 0.05) by 44.9 ± 2.8 (control), 11.3 ± 2.4 (LC only), 29 ± 3.7 (SNP), and 45.8 ± 8.7% (Iso). The reductions at LC only and SNP sites were less than at control or Iso sites ( P < 0.05); the responses at those latter sites were not different ( P > 0.05), suggesting that the baseline change in CVC with LC is important in the attenuation of reflex vasoconstrictor responses to WBC.

Effects of cold exposure and exercise in a wet, cold antarctic climate

1965 ◽  
Vol 20 (3) ◽  
pp. 417-422 ◽  
Author(s):  
G. M. Budd
Keyword(s):  
Physical Fitness ◽  
Cold Exposure ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Finger Temperature ◽  
Arterial Blood ◽  
Before And After ◽  
Tissue Insulation ◽  
Body Cooling ◽  
Whole Body Cooling

Six men were studied before and after 6 weeks of strenuous outdoor work and cold exposure—often in wet clothing—on Heard Island in the Antarctic. Physical fitness increased significantly, while subcutaneous fat and arterial blood pressure decreased significantly. The response of rectal temperature and shivering to a 2-hr period of whole-body cooling did not change significantly (although shivering tended to decrease), suggesting that the reduction in insulation caused by loss of fat was balanced by an increase in the insulation of other tissues. Finger temperature fell more rapidly, there was less cold vasodilatation, and the gradient of skin temperature between elbow and finger increased significantly, suggesting that heat was conserved by means of countercurrent heat exchanges and enhanced vasoconstriction. Discomfort from cold did not change. These results support those of a previous study at Mawson, Antarctica. Frostbite of one subject's hands, which grossly impaired touch sensation and caused marked intolerance to cold, produced no obvious changes in the response to cold of finger temperature. vasomotor adaptation to cold; cold vasodilatation; tissue insulation; subcutaneous fat; shivering; subjective responses to cold; frostbite sequelae; finger temperature before and after cold injury; physical fitness; acclimatization to cold Submitted on September 8, 1964

Local ascorbate administration inhibits the adrenergic vasoconstrictor response to local cooling in the human skin

2010 ◽  
Vol 108 (2) ◽  
pp. 328-333 ◽  
Author(s):  
Fumio Yamazaki
Keyword(s):  
Human Skin ◽  
Adrenergic Receptors ◽  
Whole Body ◽  
Antioxidant Supplementation ◽  
Local Cooling ◽  
Vasoconstrictor Response ◽  
Increased Sensitivity ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Β Adrenergic Receptors

Local cooling (LC) of nonglabrous skin causes vasoconstriction via the adrenergic and removal of nitric oxide (NO) systems. Since cooling increases reactive oxygen species in smooth muscle cells and induces increased sensitivity of α-adrenergic receptors, antioxidant supplementation may attenuate the vasoconstrictor response to skin LC via adrenergic and/or NO systems. To test this hypothesis, we examined the effects of acute l-ascorbate (Asc, 10 mM) supplementation in human skin on the vasoconstrictor responses to LC in skin with and without NO synthase (NOS) inhibition or adrenergic receptor blockade. In a three-part study, forearm sites were instrumented with microdialysis fibers, local coolers, and laser-Doppler flow (LDF) probes in healthy volunteers. Sites were cooled from 34 to 24°C at −1°C/min and maintained at 24°C for 20 min ( parts 1 and 2) or 30 min ( part 3). During the last 10 min of LC in parts 1 and 2, whole body cooling was performed to increase sympathetic vasoconstrictor activity. Cutaneous vascular conductance (CVC) was calculated as the ratio of LDF to blood pressure and expressed relative to the baseline value before cooling. Treatments in each part were as follows: part 1) untreated, Asc; part 2) NG-nitro-l-arginine methyl ester (l-NAME) to inhibit NOS, combined l-NAME + Asc; part 3) yohimbine (YOH) + propranolol (PRO) to antagonize α- and β-adrenergic receptors and combined YOH + PRO + Asc. CVC reduction during LC was smaller ( P < 0.001) at Asc sites (−31 ± 4%) than at untreated sites (−56 ± 5%). LC-induced reduction in CVC was smaller ( P < 0.05) at l-NAME + Asc sites (−23 ± 8%) than at l-NAME sites (−43 ± 7%). LC-induced reduction in CVC did not differ between at PRO + YOH sites (−56 ± 3%) and at PRO + YOH + Asc sites (−50 ± 3%). These findings suggest that antioxidant supplementation inhibits the vasoconstrictor response to direct cooling through an adrenoceptor-dependent mechanism in human skin.

Relative roles of local and reflex components in cutaneous vasoconstriction during skin cooling in humans

2006 ◽  
Vol 100 (6) ◽  
pp. 2083-2088 ◽  
Author(s):  
Guy E. Alvarez ◽  
Kun Zhao ◽  
Wojciech A. Kosiba ◽  
John M. Johnson
Keyword(s):  
Reflex Response ◽  
Whole Body ◽  
Local Cooling ◽  
Doppler Flowmetry ◽  
Peltier Cooler ◽  
Vasoconstrictor Response ◽  
Skin Cooling ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Independent Effects

The reduction in skin blood flow (SkBF) with cold exposure is partly due to the reflex vasoconstrictor response from whole body cooling (WBC) and partly to the direct effects of local cooling (LC). Although these have been examined independently, little is known regarding their roles when acting together, as occurs in environmental cooling. We tested the hypothesis that the vasoconstrictor response to combined LC and WBC would be additive, i.e., would equal the sum of their independent effects. We further hypothesized that LC would attenuate the reflex vasoconstrictor response to WBC. We studied 16 (7 women, 9 men) young (30.5 ± 2 yr) healthy volunteers. LC and WBC were accomplished with metal Peltier cooler-heater probe holders and water-perfused suits, respectively. Forearm SkBF was monitored by laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF/blood pressure. Subjects underwent 15 min of LC alone or 15 min of WBC with and without simultaneous LC, either at equal levels (34–31°C) or as equipotent stimuli (34–28°C LC; 34–31°C WBC). The fall in CVC with combined WBC and LC was greater ( P < 0.05) than for either alone (57.0 ± 5% combined vs. 39.2 ± 6% WBC; 34.4 ± 4% LC) with equipotent cooling, but it was only significantly greater than for LC alone with equal levels of cooling (51.3 ± 8% combined vs. 29.5 ± 4% LC). The sum of the independent effects of WBC and LC was greater than their combined effects (74.9 ± 4 vs. 51.3 ± 8% equal and 73.6 ± 7 vs. 57.0 ± 5% equipotent; P < 0.05). The fall in CVC with WBC at LC sites was reduced compared with control sites (17.6 ± 2 vs. 42.4 ± 8%; P < 0.05). Hence, LC contributes importantly to the reduction in SkBF with body cooling, but also suppresses the reflex response, resulting in a nonadditive effect of these two components.

scholarly journals Distribution and Severity of Hypoxic-Ischemic Lesions on Brain MRI Following Therapeutic Cooling: Selective Head Versus Whole Body Cooling

2011 ◽  
Vol 70 ◽  
pp. 722-722
Author(s):  
S Sarkar ◽  
J R Bapuraj ◽  
S M Donn ◽  
I Bhagat ◽  
J D Barks
Keyword(s):  
Brain Mri ◽  
Whole Body ◽  
Body Cooling ◽  
Whole Body Cooling

The Cooling Power of Pigeon Wings

1991 ◽  
Vol 155 (1) ◽  
pp. 193-202 ◽  
Author(s):  
ALBERT CRAIG ◽  
JACQUES LAROCHELLE
Keyword(s):  
Body Temperature ◽  
Heat Production ◽  
Heat Dissipation ◽  
Experimental System ◽  
Whole Body ◽  
Cooling Power ◽  
Wind Speeds ◽  
Maximum Value ◽  
Body Cooling ◽  
Whole Body Cooling

The rate of heat loss through the stretched wings (Hwings) was studied in resting pigeons preheated to a body temperature (43.7°C) within the range of those recorded during flight. The experimental system was designed to allow the calculation of Hwings from the increase in whole-body cooling rates resulting from exposure of the wings to various wind speeds (0–50 km h−1) at 23°C. The maximum value of HWings was 3.8 W, less than twice the heat production of a resting pigeon. This indicates that the contribution of the wings to heat dissipation during flight may not be nearly as important as has been supposed. At low windspeeds (0–12.5 km h−1), HWings corresponded to about 40% of the resting rate of heat production, and this value is discussed in connection with the various wing postures observed in hyperthermic birds.

The effect of whole body cooling in asphyxiated neonates with resource limitation: Challenges and experience

2018 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Rahul Sinha ◽  
K Venkatnarayan ◽  
Vandana Negi ◽  
Kirandeep Sodhi ◽  
BM John
Keyword(s):  
Resource Limitation ◽  
Whole Body ◽  
Body Cooling ◽  
Whole Body Cooling

scholarly journals An In Vivo Assessment of Regional Brain Temperature during Whole-Body Cooling for Neonatal Encephalopathy

2020 ◽  
Vol 220 ◽  
pp. 73-79.e3
Author(s):  
Tai-Wei Wu ◽  
Jessica L. Wisnowski ◽  
Robert F. Geisler ◽  
Aaron Reitman ◽  
Eugenia Ho ◽  
...  
Keyword(s):  
Brain Temperature ◽  
Whole Body ◽  
Neonatal Encephalopathy ◽  
Regional Brain ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
In Vivo Assessment

Subcutaneous fat necrosis, a rare but serious side effect of hypoxic-ischemic encephalopathy and whole-body hypothermia

2019 ◽  
Vol 47 (9) ◽  
pp. 986-990 ◽  
Author(s):  
Mahdi Alsaleem ◽  
Lina Saadeh ◽  
Valerie Elberson ◽  
Vasantha H.S. Kumar
Keyword(s):  
Therapeutic Hypothermia ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Subcutaneous Fat Necrosis ◽  
P Values ◽  
Life Threatening ◽  
The Mean ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Ischemic Encephalopathy

Abstract Objective To describe the clinical characteristics and risk factors in infants with subcutaneous fat necrosis (SFN) following therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE). Methods A case-control study was performed by a retrospective chart review of infants with moderate or severe HIE admitted to a level IV regional perinatal center and who underwent whole-body cooling. Results A total of 14 (8.1%) of 171 infants with moderate or severe HIE who underwent whole-body cooling developed SFN during hospitalization. There were more females [71% (10/14)] and large-for-gestational age (LGA) infants [28% (4/14)] in the SFN group vs. 36% females (57/157) and 8% LGA infants (13/157) in the group without SFN (P-values of 0.009 and 0.015, respectively). The mean lowest platelet count was lower 108 ± 55 109/L vs. 146 ± 62 109/L and the mean highest calcium level was higher 11.3 ± 2.5 vs. 10.6 ± 0.8 mg/dL in infants with SFN vs. infants without SFN, respectively (P-values of 0.0078 and 0.006, respectively). Distribution of skin lesions followed distinctive patterns representing the areas with direct contact with the cooling blanket. One infant developed severe, life-threatening hypercalcemia that required aggressive management, including diuretics, corticosteroids and bisphosphonates. Conclusion Although SFN is a rare complication of therapeutic hypothermia, it can be a life-threatening condition if complicated by severe hypercalcemia. Infants who undergo therapeutic hypothermia for HIE need regular skin examinations to evaluate for SFN. If SFN is identified, monitoring of serum calcium levels to prevent life-threatening hypercalcemia is recommended.

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