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Biological Research For Nursing Jul 2011Infrared thermal imaging, or thermography, is a technique used to measure body surface temperature in the study of thermoregulation. Researchers are beginning to use... (Clinical Trial)
Clinical Trial
INTRODUCTION
Infrared thermal imaging, or thermography, is a technique used to measure body surface temperature in the study of thermoregulation. Researchers are beginning to use this novel methodology to study cancer, peripheral vascular disease, and wound management.
METHODS
The authors tested the feasibility of using an FLIR SC640 uncooled, infrared camera to measure body temperature in neonates housed in heated, humid incubators. The authors examined thermograms to analyze distributions between central and peripheral body temperature in extremely low birth weight infants. The authors have also used this technology to examine the relationship between body temperature and development of necrotizing enterocolitis in premature infants.
RESULTS
Handheld, uncooled, infrared cameras are easy to use and produce high-quality thermograms that can be visualized in grayscale or color palettes to enhance qualitative and quantitative analyses.
CONCLUSION
Future research will benefit from the use of this noninvasive, inexpensive measurement tool. Nurse researchers can use this methodology in adult and infant populations to study temperature differentials present in pathological conditions.
Topics: Adult; Body Temperature; Body Temperature Regulation; Clinical Nursing Research; Enterocolitis, Necrotizing; Feasibility Studies; Humans; Incubators, Infant; Infant; Infant, Newborn; Infant, Premature; Infrared Rays; Pilot Projects; Thermography
PubMed: 21586499
DOI: 10.1177/1099800411403467 -
Poultry Science May 2015The wattles and comb of chickens are important for thermoregulation allowing for heat exchange during high temperatures. These integumentary tissues are sometimes... (Randomized Controlled Trial)
Randomized Controlled Trial
The wattles and comb of chickens are important for thermoregulation allowing for heat exchange during high temperatures. These integumentary tissues are sometimes trimmed to prevent tears if caught on cage equipment and to also improve feed efficiency; however, the procedure itself could be painful to chicks. Our objective was to determine the effect of trimming the comb and wattles on behavior, BW, feed usage, and the surface temperature of pullets. The wattles and comb of Leghorns were partially trimmed at 21 d age (n = 6 cages, 13 chicks each) with another 6 cages serving as controls. Behaviors were recorded 3 times daily for 1 h starting at 0800, 1200, and 1500 using instantaneous scan sampling observations conducted every 5 min prior to, on the d of, and after the trim. Group BW at 21, 28, and 36 d age and the amount of feed used for 7 d beginning at 21 and 29 d age were measured per cage. At 1300 h on d before and after the trim, thermal images of the pullet's beak, comb, eye, wattle, and shank were randomly taken on 3 pullets/cage. Smaller proportions of trimmed chicks were eating and greater proportions were sitting on the d of the trim as compared to the controls with the opposite trend occurring on 4 d post-trim (treatment by age interaction, P = 0.03 and 0.0001, respectively). Standing behavior differed only on the d of the trim where smaller proportions of trimmed pullets stood as compared to intact controls (treatment by age interaction, P = 0.0002). Trimming the comb and wattles did not affect preening, running, BW, feed utilization, and the surface temperature of the pullet. The indices of behavior suggest that on the d of the trim, pullets may have experienced temporary distress, but they returned to normal behavior by 5 h post-trim with no long-term effect on BW, feed usage, or surface body temperature.
Topics: Aging; Animal Husbandry; Animal Welfare; Animals; Beak; Behavior, Animal; Body Temperature Regulation; Chickens; Comb and Wattles; Female
PubMed: 25796274
DOI: 10.3382/ps/pev066 -
Journal of Dairy Science Feb 2021Multiparous, nonlactating pregnant cows are negatively affected by heat stress, but the effect of heat stress on more thermotolerant pregnant heifers has received less...
Multiparous, nonlactating pregnant cows are negatively affected by heat stress, but the effect of heat stress on more thermotolerant pregnant heifers has received less attention. Our objective was to characterize the effect of late-gestation heat abatement on thermoregulatory responses and subsequent milk production of nulliparous Holstein heifers. Pregnant heifers, blocked by body condition score (BCS) and predicted transmitting ability (PTA) for milk, were enrolled in either heat stress (HT, shade of freestall barn; n = 16) or cooling (CL, shade of freestall barn, water soakers, and fans; n = 15) environments during the last 60 d of pregnancy (~8 weeks). Rectal temperature (RT; thermometer), respiration rate (RR; breaths/min), sweating rate (SR; VapoMeter, Delfin Technologies, Kuopio, Finland), and skin temperature (ST; infrared thermometer) were measured thrice weekly from enrollment to calving. Vaginal temperature (VT; i-button intravaginal device) was measured every 10 min for 7 consecutive days at wk -8, -6, -4, and -2 relative to calving and averaged hourly. Daily thermoregulatory patterns assessed by SR and ST, were measured every 4 h over a 36-h time interval at wk -6, -4, and -2 relative to calving. Upon calving, milk, protein, and fat yields were recorded twice daily for 15 wk. The average temperature-humidity index (Hobo Pro temperature probe, Onset Computer Corporation, Pocasset, MA) in the barn during the precalving period was 77 (minimum of 72, maximum of 82). Only heifers that gave birth to a female calf (CL = 12, HT = 14) were included in the statistical analysis. In the precalving period, CL heifers had lower RR (44.3 vs. 60.0 ± 1.6 breaths/min), RT (38.7 vs. 38.8 ± 0.04°C), unshaved ST (34.7 vs. 35.3 ± 0.17°C), and unshaved SR (19.0 vs. 35.2 ± 1.9 g/mh), relative to HT heifers. Additionally, VT was lower in CL heifers during wk -4, and -2, specifically during early morning and early afternoon hours. When measured over a 36-h time interval, ST and SR were lower in CL heifers, when compared with HT heifers for all weeks. Notably, ST was reduced overnight and SR was reduced during the daytime. Cooled heifers had higher milk yield (35.8 vs. 31.9 ± 1.4 kg/d), when compared with HT heifers. Similar to multiparous cows, our data indicate that actively cooling heifers in late pregnancy is effective in promoting thermoregulation and results in elevated milk production postcalving.
Topics: Animals; Body Temperature Regulation; Cattle; Cattle Diseases; Cold Temperature; Dairying; Female; Finland; Gestational Age; Heat Stress Disorders; Heat-Shock Response; Hot Temperature; Humidity; Lactation; Milk; Pregnancy; Respiratory Rate; Temperature
PubMed: 33246618
DOI: 10.3168/jds.2020-18998 -
Journal of Comparative Physiology. B,... Nov 2022Torpor is characterized by an extreme reduction in metabolism and a common energy-saving strategy of heterothermic animals. Torpor is often associated with cold...
Torpor is characterized by an extreme reduction in metabolism and a common energy-saving strategy of heterothermic animals. Torpor is often associated with cold temperatures, but in the last decades, more diverse and flexible forms of torpor have been described. For example, tropical bat species maintain a low metabolism and heart rate at high ambient and body temperatures. We investigated whether bats (Nyctalus noctula) from the cooler temperate European regions also show this form of torpor with metabolic inhibition at high body temperatures, and whether this would be as pronounced in reproductive as in non-reproductive bats. We simultaneously measured metabolic rate, heart rate, and skin temperature in non-reproductive and pregnant females at a range of ambient temperatures. We found that they can decouple metabolic rate and heart rate from body temperature: they maintained an extremely low metabolism and heart rate when exposed to ambient temperatures changing from 0 to 32.5 °C, irrespective of reproductive status. When we simulated natural temperature conditions, all non-reproductive bats used torpor throughout the experiment. Pregnant bats used variable strategies from torpor, to maintaining normothermy, or a combination of both. Even a short torpor bout during the day saved up to 33% of the bats' total energy expenditure. Especially at higher temperatures, heart rate was a much better predictor of metabolic rate than skin temperature. We suggest that the capability to flexibly save energy across a range of ambient temperatures within and between reproductive states may be an important ability of these bats and possibly other temperate-zone heterotherms.
Topics: Animals; Body Temperature Regulation; Chiroptera; Energy Metabolism; Female; Skin Temperature; Torpor
PubMed: 35939092
DOI: 10.1007/s00360-022-01452-7 -
Physiological Reports Jan 2020Women with ovulatory menstrual cycles show an increase in body temperature in the luteal phase, compared with follicular phase, particularly during the night. Several,...
Women with ovulatory menstrual cycles show an increase in body temperature in the luteal phase, compared with follicular phase, particularly during the night. Several, albeit not all, studies reported higher energy expenditure in the luteal phase compared with follicular phase. Q of biological reactions lies between 2.0 and 3.0, predicting a 7-12% increase in energy expenditure when body temperature rises by 1°C. In this study, temperature dependence of energy expenditure was assessed by comparing changes in sleeping energy expenditure and thermoregulation with menstrual cycle in 9 young females. Energy expenditure was measured using a metabolic chamber, in which sleep was recorded polysomnographically, and core body temperature and skin temperature were continuously monitored. Distal-to-proximal skin temperature gradient was assessed as an index of heat dissipation. In the luteal phase, a significant increase in average core body temperature (+0.27°C) and energy expenditure (+6.9%) were observed. Heat dissipation was suppressed during the first 2 hr of sleep in the luteal phase, compared with follicular phase. Rise in basal body temperature in the luteal phase was accompanied by increased energy expenditure and suppressed heat dissipation. The 6.9% increase in metabolic rate would require a Q of 12.4 to be attributable solely to temperature (+0.27°C), suggesting that energy expenditure in the luteal phase is enhanced through the mechanism, dependent and independent of luteal-phase rise in body temperature presumably reflects other effects of the sex hormones.
Topics: Adolescent; Adult; Body Temperature Regulation; Energy Metabolism; Female; Humans; Menstrual Cycle; Sleep
PubMed: 31981319
DOI: 10.14814/phy2.14353 -
Journal of the American Association For... Sep 2022Noninvasive blood pressure measurement devices have gained popularity in recent years as an alternative to radiotelemetry and other invasive blood pressure measurement...
Noninvasive blood pressure measurement devices have gained popularity in recent years as an alternative to radiotelemetry and other invasive blood pressure measurement techniques. While many factors must be considered when choosing a measurement method, specific variables should be evaluated when using a tail-cuff blood pressure technique. Rodents have complex and dynamic thermal biology processes that involve fluctuating vasomotor tone of the tail. This and other factors that affect vascular tone, such as the autonomic response to stress, significantly affect peripheral blood flow. Awareness and consideration of thermoregulatory states and vasomotor tone can increase success and decrease variability when measuring blood pressure measurements using a tail-cuff measurement technique.
Topics: Animals; Blood Pressure; Blood Pressure Determination; Body Temperature Regulation; Rodentia; Tail
PubMed: 35948400
DOI: 10.30802/AALAS-JAALAS-22-000006 -
Journal of Athletic Training Aug 2015Current treatment recommendations for American football players with exertional heatstroke are to remove clothing and equipment and immerse the body in cold water. It is...
CONTEXT
Current treatment recommendations for American football players with exertional heatstroke are to remove clothing and equipment and immerse the body in cold water. It is unknown if wearing a full American football uniform during cold-water immersion (CWI) impairs rectal temperature (Trec) cooling or exacerbates hypothermic afterdrop.
OBJECTIVE
To determine the time to cool Trec from 39.5°C to 38.0°C while participants wore a full American football uniform or control uniform during CWI and to determine the uniform's effect on Trec recovery postimmersion.
DESIGN
Crossover study.
SETTING
Laboratory.
PATIENTS OR OTHER PARTICIPANTS
A total of 18 hydrated, physically active, unacclimated men (age = 22 ± 3 years, height = 178.8 ± 6.8 cm, mass = 82.3 ± 12.6 kg, body fat = 13% ± 4%, body surface area = 2.0 ± 0.2 m(2)).
INTERVENTION(S)
Participants wore the control uniform (undergarments, shorts, crew socks, tennis shoes) or full uniform (control plus T-shirt; tennis shoes; jersey; game pants; padding over knees, thighs, and tailbone; helmet; and shoulder pads). They exercised (temperature approximately 40°C, relative humidity approximately 35%) until Trec reached 39.5°C. They removed their T-shirts and shoes and were then immersed in water (approximately 10°C) while wearing each uniform configuration; time to cool Trec to 38.0°C (in minutes) was recorded. We measured Trec (°C) every 5 minutes for 30 minutes after immersion.
MAIN OUTCOME MEASURE(S)
Time to cool from 39.5°C to 38.0°C and Trec.
RESULTS
The Trec cooled to 38.0°C in 6.19 ± 2.02 minutes in full uniform and 8.49 ± 4.78 minutes in control uniform (t17 = -2.1, P = .03; effect size = 0.48) corresponding to cooling rates of 0.28°C·min(-1) ± 0.12°C·min(-1) in full uniform and 0.23°C·min(-1) ± 0.11°C·min(-1) in control uniform (t17 = 1.6, P = .07, effect size = 0.44). The Trec postimmersion recovery did not differ between conditions over time (F1,17 = 0.6, P = .59).
CONCLUSIONS
We speculate that higher skin temperatures before CWI, less shivering, and greater conductive cooling explained the faster cooling in full uniform. Cooling rates were considered ideal when the full uniform was worn during CWI, and wearing the full uniform did not cause a greater postimmersion hypothermic afterdrop. Clinicians may immerse football athletes with hyperthermia wearing a full uniform without concern for negatively affecting body-core cooling.
Topics: Body Temperature; Body Temperature Regulation; Clothing; Cold Temperature; Cross-Over Studies; Cryotherapy; Exercise; Fever; Football; Heat Stroke; Hot Temperature; Humans; Immersion; Male; Skin Temperature; United States; Water; Young Adult
PubMed: 26090706
DOI: 10.4085/1062-6050-50.6.01 -
Nature Nov 2018Large mammals that live in arid and/or desert environments can cope with seasonal and local variations in rainfall, food and climate by moving long distances, often...
Large mammals that live in arid and/or desert environments can cope with seasonal and local variations in rainfall, food and climate by moving long distances, often without reliable water or food en route. The capacity of an animal for this long-distance travel is substantially dependent on the rate of energy utilization and thus heat production during locomotion-the cost of transport. The terrestrial cost of transport is much higher than for flying (7.5 times) and swimming (20 times). Terrestrial migrants are usually large with anatomical specializations for economical locomotion, because the cost of transport reduces with increasing size and limb length. Here we used GPS-tracking collars with movement and environmental sensors to show that blue wildebeest (Connochaetes taurinus, 220 kg) that live in a hot arid environment in Northern Botswana walked up to 80 km over five days without drinking. They predominantly travelled during the day and locomotion appeared to be unaffected by temperature and humidity, although some behavioural thermoregulation was apparent. We measured power and efficiency of work production (mechanical work and heat production) during cyclic contractions of intact muscle biopsies from the forelimb flexor carpi ulnaris of wildebeest and domestic cows (Bos taurus, 760 kg), a comparable but relatively sedentary ruminant. The energetic costs of isometric contraction (activation and force generation) in wildebeest and cows were similar to published values for smaller mammals. Wildebeest muscle was substantially more efficient (62.6%) than the same muscle from much larger cows (41.8%) and comparable measurements that were obtained from smaller mammals (mouse (34%) and rabbit (27%)). We used the direct energetic measurements on intact muscle fibres to model the contribution of high working efficiency of wildebeest muscle to minimizing thermoregulatory challenges during their long migrations under hot arid conditions.
Topics: Acclimatization; Animal Identification Systems; Animal Migration; Animals; Antelopes; Body Size; Body Temperature Regulation; Botswana; Cattle; Desert Climate; Drinking; Energy Metabolism; Female; Geographic Information Systems; Hot Temperature; Humidity; Isometric Contraction; Locomotion; Mice; Muscle, Skeletal; Rabbits; Sedentary Behavior; Water
PubMed: 30356212
DOI: 10.1038/s41586-018-0602-4 -
Comparative Biochemistry and... Mar 2011Direct animal calorimetry, the gold standard method for quantifying animal heat production (HP), has been largely supplanted by respirometric indirect calorimetry owing... (Review)
Review
Direct animal calorimetry, the gold standard method for quantifying animal heat production (HP), has been largely supplanted by respirometric indirect calorimetry owing to the relative ease and ready commercial availability of the latter technique. Direct calorimetry, however, can accurately quantify HP and thus metabolic rate (MR) in both metabolically normal and abnormal states, whereas respirometric indirect calorimetry relies on important assumptions that apparently have never been tested in animals with genetic or pharmacologically-induced alterations that dysregulate metabolic fuel partitioning and storage so as to promote obesity and/or diabetes. Contemporary obesity and diabetes research relies heavily on metabolically abnormal animals. Recent data implicating individual and group variation in the gut microbiome in obesity and diabetes raise important questions about transforming aerobic gas exchange into HP because 99% of gut bacteria are anaerobic and they outnumber eukaryotic cells in the body by ∼10-fold. Recent credible work in non-standard laboratory animals documents substantial errors in respirometry-based estimates of HP. Accordingly, it seems obvious that new research employing simultaneous direct and indirect calorimetry (total calorimetry) will be essential to validate respirometric MR phenotyping in existing and future pharmacological and genetic models of obesity and diabetes. We also detail the use of total calorimetry with simultaneous core temperature assessment as a model for studying homeostatic control in a variety of experimental situations, including acute and chronic drug administration. Finally, we offer some tips on performing direct calorimetry, both singly and in combination with indirect calorimetry and core temperature assessment.
Topics: Animals; Body Temperature Regulation; Calibration; Calorimetry; Calorimetry, Indirect; Drug Tolerance; Energy Metabolism; History, 18th Century; History, 19th Century; History, 20th Century; History, 21st Century; Homeostasis; Humans; Hypothermia, Induced; Models, Animal; Nitrous Oxide
PubMed: 20427023
DOI: 10.1016/j.cbpa.2010.04.013 -
Clinical Journal of the American... Sep 2019Marathon runners develop transient AKI with urine sediments and injury biomarkers suggesting nephron damage.
BACKGROUND AND OBJECTIVES
Marathon runners develop transient AKI with urine sediments and injury biomarkers suggesting nephron damage.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
To investigate the etiology, we examined volume and thermoregulatory responses as possible mechanisms in runners' AKI using a prospective cohort of runners in the 2017 Hartford Marathon. Vitals, blood, and urine samples were collected in 23 runners 1 day premarathon and immediately and 1 day postmarathon. We measured copeptin at each time point. Continuous core body temperature, sweat sodium, and volume were assessed during the race. The primary outcome of interest was AKI, defined by AKIN criteria.
RESULTS
Runners ranged from 22 to 63 years old; 43% were men. Runners lost a median (range) of 2.34 (0.50-7.21) g of sodium and 2.47 (0.36-6.81) L of volume sweat. After accounting for intake, they had a net negative sodium and volume balance at the end of the race. The majority of runners had increases in core body temperature to 38.4 (35.8-41)°C during the race from their baseline. Fifty-five percent of runners developed AKI, yet 74% had positive urine microscopy for acute tubular injury. Runners with more running experience and increased participation in prior marathons developed a rise in creatinine as compared with those with lesser experience. Sweat sodium losses were higher in runners with AKI versus non-AKI (median, 3.41 [interquartile range (IQR), 1.7-4.8] versus median, 1.4 [IQR, 0.97-2.8] g; =0.06, respectively). Sweat volume losses were higher in runners with AKI versus non-AKI (median, 3.89 [IQR, 1.49-5.09] versus median, 1.66 [IQR, 0.72-2.84] L; =0.03, respectively). Copeptin was significantly higher in runners with AKI versus those without (median, 79.9 [IQR, 25.2-104.4] versus median, 11.3 [IQR, 6.6-43.7]; =0.02, respectively). Estimated temperature was not significantly different.
CONCLUSIONS
All runners experienced a substantial rise in copeptin and body temperature along with salt and water loss due to sweating. Sodium and volume loss sweat as well as plasma copeptin concentrations were associated with AKI in runners.
PODCAST
This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_08_13_CJASNPodcast_19_09_.mp3.
Topics: Acute Kidney Injury; Adult; Body Temperature Regulation; Body Water; Female; Humans; Male; Middle Aged; Prospective Studies; Running; Young Adult
PubMed: 31413064
DOI: 10.2215/CJN.01400219