scholarly journals Exercise activates compensatory thermoregulatory reaction in rats: a modeling study

2015 ◽  
Vol 119 (12) ◽  
pp. 1400-1410 ◽  
Author(s):  
Yeonjoo Yoo ◽  
Michelle LaPradd ◽  
Hannah Kline ◽  
Maria V. Zaretskaia ◽  
Abolhassan Behrouzvaziri ◽  
...  
Keyword(s):  
Body Temperature ◽  
Heat Generation ◽  
Heat Production ◽  
Core Body Temperature ◽  
Heat Stroke ◽  
The Body ◽  
Model Parameters ◽  
The Core ◽  
Treadmill Speed ◽  
Core Body

The importance of exercise is increasingly emphasized for maintaining health. However, exercise itself can pose threats to health such as the development of exertional heat shock in warm environments. Therefore, it is important to understand how the thermoregulation system adjusts during exercise and how alterations of this can contribute to heat stroke. To explore this we measured the core body temperature of rats ( Tc) running for 15 min on a treadmill at various speeds in two ambient temperatures ( Ta = 25°C and 32°C). We assimilated the experimental data into a mathematical model that describes temperature changes in two compartments of the body, representing the muscles and the core. In our model the core body generates heat to maintain normal body temperature, and dissipates it into the environment. The muscles produce additional heat during exercise. According to the estimation of model parameters, at Ta = 25°C, the heat generation in the core was progressively reduced with the increase of the treadmill speed to compensate for a progressive increase in heat production by the muscles. This compensation was ineffective at Ta = 32°C, which resulted in an increased rate of heat accumulation with increasing speed, as opposed to the Ta = 25°C case. Interestingly, placing an animal on a treadmill increased heat production in the muscles even when the treadmill speed was zero. Quantitatively, this “ready-to-run” phenomenon accounted for over half of the heat generation in the muscles observed at maximal treadmill speed. We speculate that this anticipatory response utilizes stress-related circuitry.

scholarly journals Reliability and Validity of the CORE Sensor to Assess Core Body Temperature during Cycling Exercise

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5932
Author(s):  
Nina Verdel ◽  
Tim Podlogar ◽  
Urša Ciuha ◽  
Hans-Christer Holmberg ◽  
Tadej Debevec ◽  
...  
Keyword(s):  
Body Temperature ◽  
Relative Humidity ◽  
Heat Load ◽  
Core Body Temperature ◽  
Heat Stroke ◽  
Reliability And Validity ◽  
The Body ◽  
Validity And Reliability ◽  
The Core ◽  
Core Body

Monitoring core body temperature (Tc) during training and competitions, especially in a hot environment, can help enhance an athlete’s performance, as well as lower the risk for heat stroke. Accordingly, a noninvasive sensor that allows reliable monitoring of Tc would be highly beneficial in this context. One such novel non-invasive sensor was recently introduced onto the market (CORE, greenTEG, Rümlang, Switzerland), but, to our knowledge, a validation study of this device has not yet been reported. Therefore, the purpose of this study was to evaluate the validity and reliability of the CORE sensor. In Study I, 12 males were subjected to a low-to-moderate heat load by performing, on two separate occasions several days apart, two identical 60-min bouts of steady-state cycling in the laboratory at 19 °C and 30% relative humidity. In Study II, 13 males were subjected to moderate-to-high heat load by performing 90 min of cycling in the laboratory at 31 °C and 39% relative humidity. In both cases the core body temperatures indicated by the CORE sensor were compared to the corresponding values obtained using a rectal sensor (Trec). The first major finding was that the reliability of the CORE sensor is acceptable, since the mean bias between the two identical trials of exercise (0.02 °C) was not statistically significant. However, under both levels of heat load, the body temperature indicated by the CORE sensor did not agree well with Trec, with approximately 50% of all paired measurements differing by more than the predefined threshold for validity of ≤0.3 °C. In conclusion, the results obtained do not support the manufacturer’s claim that the CORE sensor provides a valid measure of core body temperature.

scholarly journals Heterothermy is associated with reduced fitness in wild rabbits

2017 ◽  
Vol 13 (12) ◽  
pp. 20170521 ◽  
Author(s):  
Shane K. Maloney ◽  
Maija K. Marsh ◽  
Steven R. McLeod ◽  
Andrea Fuller
Keyword(s):  
Body Temperature ◽  
Oryctolagus Cuniculus ◽  
Reproductive Output ◽  
Core Body Temperature ◽  
The Body ◽  
The Core ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Core Body ◽  
Growth And Reproduction

An increase in variation in the 24 h pattern of body temperature (heterothermy) in mammals can be induced by energy and water deficits. Since performance traits such as growth and reproduction also are impacted by energy and water balance, we investigated whether the characteristics of the body temperature rhythm provide an indication of the reproductive success of an individual. We show that the amplitude of the daily rhythm of body temperature in wild rabbits ( Oryctolagus cuniculus ) prior to breeding is inversely related to the number of pregnancies in the subsequent seven months, while the minimum daily body temperature is positively correlated to the number of pregnancies. Because reproductive output could be predicted from characteristics of the core body temperature rhythm prior to the breeding season, we propose that the pattern of the 24 h body temperature rhythm could provide an index of animal fitness in a given environment.

scholarly journals Circadian Rhythm of Core Body Temperature (Part II): Hyperbaric Environment Influence on Circadian Rhythm of Core Body Temperature

2016 ◽  
Vol 57 (4) ◽  
pp. 19-25
Author(s):  
Joanna Słomko ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
Małgorzata Tafil-Klawe ◽  
Piotr Siermontowsk ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Body Temperature ◽  
Core Body Temperature ◽  
The Body ◽  
Hyperbaric Chamber ◽  
The Core ◽  
Hyperbaric Environment ◽  
The Mean ◽  
Core Body ◽  
Telemetric Measurement

Abstract The aim of this study was to analyse dynamic fluctuations in the circadian rhythm of the core body temperature in healthy adults exposed to conditions in a hyperbaric chamber, using fully objective-telemetric measurement methods. The study group consisted of 13 healthy males (age 32±6.4 years, height 1.85±0.1 m, body weight 84.00±6.3 kg; BMI 24.7±1.2 kg/m2). The core body temperature (CBT) was measured with the Vital Sense telemetry system. The volunteers were placed in a hyperbaric chamber, exposed to compression of 400 kPa, with the exposure plateau of approx. 30 minutes, followed by gradual decompression. The mean core temperature was 36.71°C when registered within 10 minutes before the exposure, 37.20°C during the exposure, 37.27°C one hour after the exposure, 37.36°C 2 hours after the exposure, and 37.42°C three hours after the exposure. The conducted observations show that one-hour stay in a hyperbaric chamber at a depth of 30 m results in an increase in the body temperature, particularly significant after the exposure ends, and maintained for at least 3 hours after the exposure.

scholarly journals Pathophysiology of Fever and Application of Infrared Thermography (IRT) in the Detection of Sick Domestic Animals: Recent Advances

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2316
Author(s):  
Daniel Mota-Rojas ◽  
Dehua Wang ◽  
Cristiane Gonçalves Titto ◽  
Jocelyn Gómez-Prado ◽  
Verónica Carvajal-de la Fuente ◽  
...  
Keyword(s):  
Body Temperature ◽  
Infrared Thermography ◽  
Core Body Temperature ◽  
The Body ◽  
Farm Animals ◽  
Economic Losses ◽  
Febrile Response ◽  
Temperature Range ◽  
Stable Temperature ◽  
Core Body

Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT.

scholarly journals Temperature Monitoring and Perioperative Thermoregulation

2008 ◽  
Vol 109 (2) ◽  
pp. 318-338 ◽  
Author(s):  
Daniel I. Sessler ◽  
David S. Warner ◽  
Mark A. Warner
Keyword(s):  
Body Temperature ◽  
General Anesthesia ◽  
Core Temperature ◽  
Core Body Temperature ◽  
Neuraxial Anesthesia ◽  
General Anesthetics ◽  
The Core ◽  
Core Body ◽  
Dose Dependent ◽  
Body Heat

Most clinically available thermometers accurately report the temperature of whatever tissue is being measured. The difficulty is that no reliably core-temperature-measuring sites are completely noninvasive and easy to use-especially in patients not undergoing general anesthesia. Nonetheless, temperature can be reliably measured in most patients. Body temperature should be measured in patients undergoing general anesthesia exceeding 30 min in duration and in patients undergoing major operations during neuraxial anesthesia. Core body temperature is normally tightly regulated. All general anesthetics produce a profound dose-dependent reduction in the core temperature, triggering cold defenses, including arteriovenous shunt vasoconstriction and shivering. Anesthetic-induced impairment of normal thermoregulatory control, with the resulting core-to-peripheral redistribution of body heat, is the primary cause of hypothermia in most patients. Neuraxial anesthesia also impairs thermoregulatory control, although to a lesser extent than does general anesthesia. Prolonged epidural analgesia is associated with hyperthermia whose cause remains unknown.

Monitoring of the core body temperature of cows using implantable wireless thermometers

2019 ◽  
Vol 163 ◽  
pp. 104849 ◽  
Author(s):  
Wataru Iwasaki ◽  
Shuichi Ishida ◽  
Daisuke Kondo ◽  
Yuichi Ito ◽  
Jun Tateno ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
The Core ◽  
Core Body

scholarly journals Comparison of Tympanic and Tail Temperatures in Angus and Brahman Steers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Dikmen S ◽  
Davila KMS ◽  
Rodriquez E ◽  
Scheffler TL ◽  
Oltenacu PA ◽  
...  
Keyword(s):  
Body Temperature ◽  
Repeated Measures ◽  
Core Body Temperature ◽  
The Body ◽  
Tympanic Temperature ◽  
Repeated Measure ◽  
Important Indicator ◽  
Significant Difference ◽  
Brahman Steers ◽  
Core Body

In cattle, core body temperature can be used as an important indicator of heat stress level. However, accurately recording core body temperature can be difficult and labor intensive. The objectives of the current study were 1) to compare the recorded tympanic and tail body temperature measurements in steers and 2) to determine the body temperature change of Angus and Brahman steers in a hot and humid environment. Data was analyzed using a repeated measure model where repeated measures were hourly tympanic and tail temperatures and their difference for individual steers during the day of the experiment. There was a significant breed effect (P=0.01), hour (P<0.0001) and breed by hour interaction (P<0.0001) for the tympanic temperature. Brahman steers, which are known to have superior thermotolerance, maintained a lower body temperature than the Angus steers during the afternoon under grazing conditions. In the Brahman steers there was only a minimal increase in the body temperature throughout the day, an evidence of the thermotolerance ability of the breed. In the Angus steers, which experienced an increase in their body temperature from hour to hour with a peak around 1600 hour; there was a significant difference between the tympanic and tail temperature during the times when the body temperature as measured by the tympanic recordings was the highest (1300 to 1700 hour). Our results indicate that the tympanic temperature can be used to accurately and continuously monitor core body temperature in a natural environment for up to several days and without disturbing the animal.

scholarly journals A Case Report on Osborn Waves of Hypothermia Induced LV Systolic Dysfunction

2021 ◽  
Vol 70 (2) ◽  
Author(s):  
Rajnandini Singha ◽  
Amazing Grace Siangshai ◽  
Jashlyn Lijo
Keyword(s):  
Body Temperature ◽  
Sinus Bradycardia ◽  
Core Body Temperature ◽  
Systolic Dysfunction ◽  
Left Ventricular ◽  
The Body ◽  
Qrs Complex ◽  
Pr Interval ◽  
Gradual Expansion ◽  
Core Body

Hypothermia, described as a core body temperature of < 95%, is associated with ECG alteration abnormalities. Sinus bradycardia occurs when the body temperature drops below 90°F, and is correlated with gradual prolongation of the PR interval, QRS complex, QT interval. It can progress to ventricular and atrial fibrillation at a temperature reaching 89°F, which can lead to left ventricular dysfunction. Hypothermia is connected to the osborn waves, which at the end of the QRS complex consist of additional deflection. The inferior and lateral precordial leads are seen by Osborn waves, also known as J waves, Camel hump waves and hypothermic waves. As the body temperature decreases, it becomes more pronounced and a gradual expansion of the QRS complex raises the likelihood of ventricular fibrillation causing ventricle dysfunction.

scholarly journals Skipping Breakfast for 6 Days Delayed the Circadian Rhythm of the Body Temperature without Altering Clock Gene Expression in Human Leukocytes

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2797 ◽  
Author(s):  
Hitomi Ogata ◽  
Masaki Horie ◽  
Momoko Kayaba ◽  
Yoshiaki Tanaka ◽  
Akira Ando ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Clock Gene ◽  
Core Body Temperature ◽  
The Core ◽  
Clock Gene Expression ◽  
Meal Timing ◽  
Dim Light ◽  
Core Body ◽  
Skipping Breakfast

Breakfast is often described as “the most important meal of the day” and human studies have revealed that post-prandial responses are dependent on meal timing, but little is known of the effects of meal timing per se on human circadian rhythms. We evaluated the effects of skipping breakfast for 6 days on core body temperature, dim light melatonin onset, heart rate variability, and clock gene expression in 10 healthy young men, with a repeated-measures design. Subjects were provided an isocaloric diet three times daily (3M) or two times daily (2M, i.e., breakfast skipping condition) over 6 days. Compared with the 3M condition, the diurnal rhythm of the core body temperature in the 2M condition was delayed by 42.0 ± 16.2 min (p = 0.038). On the other hand, dim light melatonin onset, heart rate variability, and clock gene expression were not affected in the 2M condition. Skipping breakfast for 6 days caused a phase delay in the core body temperature in healthy young men, even though the sleep–wake cycle remained unchanged. Chronic effects of skipping breakfast on circadian rhythms remain to be studied.

scholarly journals The Effects of Hyperbaric Exposure on Immediate and Delayed Changes in Core Temperature and Its Circadian Fluctuations

2017 ◽  
Vol 60 (3) ◽  
pp. 19-25
Author(s):  
Sławomir Kujawski ◽  
Joanna Słomko ◽  
Monika Zawadka-Kunikowska ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Core Body Temperature ◽  
The Body ◽  
Physiological Adaptation ◽  
Deep Body Temperature ◽  
Delayed Effects ◽  
Hyperbaric Exposure ◽  
Core Body ◽  
Deep Body

Abstract Changes observed in the core body temperature of divers are the result of a multifaceted response from the body to the change of the external environment. In response to repeated activities, there may be a chronic, physiological adaptation of the body’s response system. This is observed in the physiology of experienced divers while diving. The purpose of this study is to determine the immediate and delayed effects of hyperbaric exposure on core temperature, as well as its circadian changes in a group of three experienced divers. During compression at 30 and 60 meters, deep body temperature values tended to increase. Subsequently, deep body temperature values showed a tendency to decrease during decompression. All differences in core temperature values obtained by the group of divers at individual time points in this study were not statistically significant.

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