Body Surface Temperature Research Articles

A pilot study of skin stretching and blood circulation effects of dermal suctioning in dogs

Dermal suctioning has been reported to yield effects similar to those of cupping therapy in humans and horses, including pain reduction, increased blood circulation, improved flexibility, and healing. However, there is a dearth of reported outcomes concerning cupping or dermal suctioning in dogs. In this study, we examined the physiological effects of dermal suctioning in dogs. Employing the Medicell MINI pro8 device, dermal suctioning was applied to the dorsal surfaces of eight healthy beagle dogs for 20 min. Metrics such as body surface temperature, rectal temperature, pulse rate, respiratory rate, and skin pinch test results were gauged. Seven healthy beagle dogs were used as controls, and the same measurements were performed without dermal suctioning. The results showed a significant increase in the body surface temperature and skin pinch test results after dermal suctioning. We believe that the elimination of torsion in the blood vessels and nerves in the shallow fascia positively affected the thermoregulatory mechanism, resulting in an increase in body surface temperature, and also improving skin flexibility. Thus, dermal suctioning promotes subcutaneous blood circulation and improves skin flexibility in dogs. Further research is needed to identify the mechanisms underlying the effects of dermal suctioning and evaluate the stress in dogs caused by the implementation of the process.

Thermal biology of Lanthanotus borneensis (Lanthanotidae) in Sarawak, Borneo

Abstract Lanthanotus borneensis, the Bornean earless monitor, is a monotypic member of the family Lanthanotidae, and restricted to the island of Borneo. Little has been published on its field ecology. This study investigated aspects of its thermal biology through an analysis of surface body temperatures of free ranging individuals against corresponding environmental temperatures, in order to explore aspects of microhabitat utilisation in relation to thermoregulation. A generalised linear mixed model shows significant effect of air and substrate temperatures, but not of water temperature. Further, the fixed effects of substrate temperature (coefficient estimate 0.396; ) versus ambient temperature (0.264; ), is suggestive of thigmothermy as the primary mode of thermoregulation. The species does not appear to utilise specific microhabitat structures to thermoregulate, the results of these observations suggesting that it is a thermoconformer.

Which physiological measurements can characterize core and surface body temperature? A case study in stable thermal environment

Core and surface body temperature are physiological indicators commonly used in human-environment researches, but which specific body temperatures can characterize them have not been thoroughly explored. A case study was conducted in three stable thermal environments, where five kinds of body temperatures (intra-abdominal temperature, oral temperature, auditory canal temperature, breath temperature, and skin temperature) and two types of thermal perception (thermal sensation and thermal comfort) votes were regularly collected. Upon comparing measurements with theoretical classification principles, we found that both oral temperature and intra-abdominal temperature exhibited characteristics consistent with core temperature, while both mean skin temperature and breath temperature exhibited characteristics consistent with surface temperature. In addition, the comparison analysis between newly proposed indicators and gold standards further confirmed application prospects, as the average temperature difference between intra-abdominal and oral remained consistently below 0.1 °C, and the average temperature difference between skin and breath exhibited a slight fluctuation around fixed values. Generally, the findings of this study provide insights into the selection and application of body temperature indicators, while reminding researchers should not blindly follow the previous standards.

Thermographic Changes following Short-Term High-Intensity Anaerobic Exercise.

Current studies report thermographic changes following aerobic or resistance exercise but not short, vigorous anaerobic exercise. Therefore, we investigated body surface temperature changes using thermal imaging following a short session of anaerobic exercise. We studied three different regions of interest (ROIs): the legs, chest, and forehead. Thermal imaging for each participant was performed before and immediately after completing a Wingate anaerobic test and every minute during a 15 min recovery period. Immediately after the test, the maximum temperature was significantly higher in all ROIs (legs, p = 0.0323; chest, p = 0.0455; forehead, p = 0.0444) compared to pre-test values. During the recovery period, both legs showed a significant and continuous temperature increase (right leg, p = 0.0272; left leg, p = 0.0382), whereas a non-significant drop was noted in the chest and forehead temperatures. Additionally, participants with a lower anaerobic capacity exhibited a higher delta increase in surface leg temperature than participants with higher anaerobic capacities, with a minimal change in surface leg temperature. This is the first study to demonstrate body surface temperature changes following the Wingate anaerobic test. This temperature increase is attributed to the high anaerobic mechanical power outputs achieved by the leg muscles and the time taken for temperature reduction post-exercise.

362 The Influence of Supplemental Protein Level on the Intake, Digestion, and Metabolism of Beef Cattle Consuming Low-Quality, High-Fiber Roughages

Abstract Two studies were conducted to evaluate the influence of graded levels of supplemental protein on the intake, digestion, ruminal fermentation, and metabolism of beef cows consuming low-quality forage base diets (6% CP and 74% NDF). For both studies, 15 ruminally cannulated cows (4/5 yrs age, 803 and 757 kg = avg BW for study 1 and 2, respectively) were stratified by BW and, within stratum, randomly assigned to three supplemental treatment groups (n = 5). In study 1, cows were assigned to the following treatments: 1) control, no supplement; 2) 0.25 % BW of a 20% CP supplement; and 3) 0.25 % BW of a 40% supplement. Both supplements were composed of soybean meal and ground corn with the composition adjusted to hit the target CP level. In study 2, cows were assigned to the following alfalfa pellet supplement treatments: 1) control, no supplement; 2) 0.20 % BW of alfalfa pellets, and 3) 0.40 % BW of alfalfa pellets. In study 1, forage intake, DM fill, liquid fill and total tract digestibility were not influenced by supplemental treatment (P ≥ 0.49). However, total DM intake increased linearly (P = 0.02) with increasing supplemental protein, with the 40% CP supplemented cows consuming 39% more DM than control cows. No treatment differences (P ≥ 0.97) were observed for heart rate or surface temperature just before feeding (hour 0) nor 5 hours post-feeding averaging 46.0 bpm, 15.3°C, and 35.2°C, respectively. In study 2, both forage intake and total intake increased linearly (P ≤ 0.02) with increasing amounts of supplemental alfalfa. Cattle supplemented alfalfa pellets at 0.4% of BW had 33 and 71% greater forage and total DM intake compared with non-supplemented control cows, respectively. In contrast, there were no treatment effects (P ≥ 0.11) on DM fill and total tract digestibility averaging 15.73 kg and 44.99%, respectively. In contrast, liquid fill tended to increase (P = 0.08) linearly with increasing levels of supplemental alfalfa. Heart rate nor surface temperature prior to feeding and 5-hours post feeding were influenced (P ≥ 0.83) by the addition of supplemental alfalfa averaging 51.91 bpm, 15.05°C and 31.75°C, respectively. In summary, overall total DM intake was enhanced with the addition of supplemental protein, however, only modest effects were observed in ruminal fill and total tract digestion. Additionally, heart rate and surface body temperatures were not influenced by supplemental treatments under the conditions of these studies.

Single-facility study of the effectiveness of rehabilitation therapy using wearable hybrid assistive limb for patients with bleeding disorders: study protocol for a randomised controlled trial

IntroductionHaemophilic arthropathy, a serious complication of haemophilia, results from recurrent joint bleeding, causing progressive joint damage and severely impacting patient quality of life. Rehabilitation therapy (RT) effectively addresses declining physical...

PSIII-3 Correlations Between Body Surface and Rectal Temperature of Newly Weaned Sows

Abstract There is interest in using body temperature changes in sows as an indicator of the onset of estrus. However, the optimum location to measure body temperature has not been established. The objective of this study was to evaluate the relationships between sow body surface temperature (SBST) measured at various locations and rectal temperature. The study involved 98 multiparous sows weaned in 6 groups between September and November. Sows were housed in individual stalls and were checked daily for standing reflex from day 3 to 7 post-weaning. Temperature measurements were taken daily for 10 days post-weaning [at 06:15 (feeding time), 07:00, 07:30 (heat checking time), 09:00, 11:00, 13:00, 15:00, 17:00, 19:00, 21:00, and 23:00]. Surface temperature was measured using a handheld thermal camera at 4 locations: outer ear, back of the head, vulva, and ham. Rectal temperature was measured using a clinical thermometer. The ambient temperature in the room was measured at the same times as the animal measurements were taken. The PROC CORR procedure of SAS was used to determine correlations between SBST, rectal temperature, and average room temperature at the time of each measurement (RMT). All correlations between SBST at the different measurement locations were strong and positive (P < 0.0001; Table 1) with r values ranging from 0.64 (between vulva and the outer ear) to 0.89 (between vulva and ham). However, correlations between SBST and rectal temperature were relatively weak (range r = 0.14 to 0.18; P < 0.0001). Rectal temperature was not correlated with RMT (r = 0.02; P = 0.12); correlations between RMT and SBST measurements were positive, with the strongest correlations being with the outer ear and the back of the head (r = 0.45 and 0.50, respectively; P < 0.0001). In conclusion, this study suggests strong relationships between body surface temperatures at different locations but relatively weak relationships between these measurements and rectal temperature. In addition, these results suggest room temperature has a greater influence on body surface temperature than on rectal temperature.

Effect of shading on the physiological and reproductive parameters in Nelore cows.

This study aimed to evaluate the physiological and reproductive parameters of Nelore cows under various microclimatic conditions. The experiment was performed in Central Brazil, which has a tropical climate with dry winters and rainy summers. The experimental groups were divided into an area with shading (5.8 trees/ha; n = 42) and an area with little shading (0.4 trees/ha; n = 42). The physiological (heart rate, respiratory rate, rectal temperature, surface body temperature, and vaginal temperature) and reproductive (estrus detection, conception rate, and rate of pregnancy loss) parameters were then assessed. The rectal temperature (p = 0.002); surface body temperature on the flanks, forehead, and shoulder (p < 0.001); and vaginal temperature (p < 0.001) of cows in the group with shading were significantly lower than those of cows in the group without shading. Estrus was higher (p = 0.08) in the shaded group; however, no effect was observed on conception and pregnancy loss rates. In conclusion, shading (5.8 trees/ha) provided better thermal comfort for Nelore animals in the tropical climatic region. However, this did not affect their performance after fixed-time artificial insemination.

It's cool to be stressed: Body surface temperatures track sympathetic nervous system activation during acute stress.

The acute stress response can be considered the primary evolutionary adaptation to maximise fitness in the face of unpredictable environmental challenges. However, the difficulties of assessing physiology in natural environments mean comparatively little is known about how response variation influences fitness in free-living animals. Currently, determining acute stress physiology typically involves blood sampling or cardiac monitoring. Both require trapping and handling, interrupting natural behaviour, and potentially biasing our understanding toward trappable species/individuals. Importantly, limits on repeated sampling also restrict response phenotype characterisation, vital for linking stress with fitness. Surface temperature dynamics resulting from peripheral vasomotor activity during acute stress are increasingly promoted as alternative physiological stress indicators, which can be measured non-invasively using infrared thermal imaging, overcoming many limitations of current methods. Nonetheless, which aspects of stress physiology they represent remains unclear, as the underlying mechanisms are unknown. To date, validations have primarily targeted the hypothalamic-pituitary-adrenal axis, when the sympathetic-adrenal-medullary (SAM) system is likely the primary driver of vasomotor activity during acute stress. To address this deficit, we compared eye and bill region surface temperatures - measured using thermal imaging - with SAM system activity - measured as heart-rate-variability via electrocardiogram telemetry - in wild-caught captive house sparrows (Passer domesticus), during capture and handling. We found lower body surface temperatures were associated with increased sympathetic nervous system activation. Consequently, our data confirm body surface temperatures can act as a proxy for sympathetic activation during acute stress, providing potentially transformative opportunities for linking the acute stress response with fitness in the wild.

RNA-seq Analysis Reveals Potential Synergic Effects of Acetate and Cold Exposure on Interscapular Brown Adipose Tissue in Mice.

Brown adipose tissue (BAT) exhibits remarkable morphological and functional plasticity in response to environmental (e.g., cold exposure) and nutrient (e.g., high-fat diet) stimuli. Notably, a number of studies have showed that acetate, the main fermentation product of dietary fiber in gut, profoundly influences the differentiation and activity of BAT. However, the potential synergic or antagonistic effects of acetate and cold exposure on BAT have not been well examined. In the present study, the C57BL/6J mice were treated with acetate at the systemic level before a short period of cold exposure. Physiological parameters including body weight, blood glucose, and Respiratory Exchange Ratio (RER) were monitored, and thermal imaging of body surface temperature was captured. Moreover, the transcriptome profiles of interscapular BAT were also determined and analyzed afterwards. The obtained results showed that acetate treatment prior to cold exposure could alter the gene expression profile, as evidenced by significant differential clusters between the two groups. GO analysis and KEGG analysis further identified differentially expressed genes being mainly enriched for a number of biological terms and pathways related to lipid metabolism and brown adipose activity such as "G-protein-coupled receptor activity", "cAMP metabolic process", "PPAR signaling pathway", and "FoxO signaling pathway". GSEA analysis further suggested that activation status of key pathways including "PPAR signaling pathway" and "TCA cycle" were altered upon acetate treatment. Taken together, our study identified the potential synergistic effect of acetic acid with cold exposure on BAT, which highlighted the positive dietary and therapeutic aspects of acetate.

Assessing aerobic physical efficiency through temple surface temperature measurements during light, heavy exercise, and recovery

The study was conducted to determine thecorrelation between the selected measures of aerobic physical efficiency and changes in the temple surface temperature in response to light and heavy exercise. 25 physically active men aged 19–25 were recruited for the study. They performed a graded exercise test on a cycle ergometer to measure maximum power (Pmax) and a test verifying the value of maximum oxygen uptake (VO2max). Then, two 3-min submaximal efforts with constant-intensity of 2.2 W·kgLBM−1 and 5 W·kgLBM−1, respectively were performed. During the constant-intensity efforts, the temperature of the temple surface was measured. Then, the difference between the temperature of the temple measured at the end of the exercise and the temperature measured at the beginning of the exercise was calculated (ΔT1-2.2, ΔT1-5, respectively). It was shown that ΔT1-2.2 correlated statistically significantly with VO2max (ml·min−1·kg−1) (r = 0.49; p = 0.01) and Pmax (W·kg−1) (r = 0.41, p = 0.04). Moreover, ΔT1-5 correlated statistically significantly with VO2max (l·min−1) (r = − 0.41; p = 0.04). Changes in body surface temperature in response to light exercise positively correlate with measurements of aerobic physical efficiency, such as VO2max and Pmax. When the exercise intensity is high (5 W·kgLBM−1), the correlation between exercise body temperature changes and VO2max becomes negative.

Organic selenium and vitamin E for gilts and sows bred in equatorial climate.

The aim of this study was to evaluate the dietary supplementation of organic selenium (Se) and vitamin E for sows from 1st and 2nd parity order, without adiabatic cooling on physiological parameters, reproductive performance, milk composition, litter performance and blood concentrations of antioxidant enzymes. A total of 96 sows were allotted in a 4 × 2 completely factorial design, with 4 experimental groups and 2 parity orders (1st and 2nd). The experimental groups consisted of: ACCon-sows receiving adiabatic cooling and no dietary supplementation of organic Se and vitamin E; WACCon-sows without adiabatic cooling and no dietary supplementation of organic Se and vitamin E; WACSe-sows without adiabatic cooling with dietary supplementation of 0.3 mg/kg organic Se; WACSeE-sows without adiabatic cooling with dietary supplementation of 0.3 mg/kg organic Se and 90 UI of vitamin E. ACCon Sows had lower respiratory rate, rectal temperature and body surface temperature when compared to the others sows (p < 0.05). Sows without evaporative cooling had lower daily milk production and weaned litters with lower weight and average daily gain when compared to the other groups (p < 0.05). ACCon sows presented higher weaned piglets to WACSeE sows. WACSeE Sows had higher concentrations of GSH-Px when compared to other experimental groups and higher levels of SOD than sows from ACCon and WACSe. Piglets of sows from WACSeE group presented higher levels of GSH-Px and SOD when compared to the other experimental groups. ACCon sows have higher milk yield and higher litter weight than others groups. Under equatorial climate conditions, dietary supplementation of organic Se and vitamin E from first and second parity order sows does not respond efficiently on thermoregulatory physiology and performance compared to adiabatic cooling, but modulates the enzymatic antioxidant balance of sows and piglets.

Reduction in Cold Stress in an Innovative Metabolic Cage Housing System Increases Animal Welfare in Laboratory Mice.

Housing in metabolic cages can induce a pronounced stress response. Metabolic cage systems imply housing mice on metal wire mesh for the collection of urine and feces in addition to monitoring food and water intake. Moreover, mice are single-housed, and no nesting, bedding, or enrichment material is provided, which is often argued to have a not negligible impact on animal welfare due to cold stress. We therefore attempted to reduce stress during metabolic cage housing for mice by comparing an innovative metabolic cage (IMC) with a commercially available metabolic cage from Tecniplast GmbH (TMC) and a control cage. Substantial refinement measures were incorporated into the IMC cage design. In the frame of a multifactorial approach for severity assessment, parameters such as body weight, body composition, food intake, cage and body surface temperature (thermal imaging), mRNA expression of uncoupling protein 1 (Ucp1) in brown adipose tissue (BAT), fur score, and fecal corticosterone metabolites (CMs) were included. Female and male C57BL/6J mice were single-housed for 24 h in either conventional Macrolon cages (control), IMC, or TMC for two sessions. Body weight decreased less in the IMC (females-1st restraint: -6.94%; 2nd restraint: -6.89%; males-1st restraint: -8.08%; 2nd restraint: -5.82%) compared to the TMC (females-1st restraint: -13.2%; 2nd restraint: -15.0%; males-1st restraint: -13.1%; 2nd restraint: -14.9%) and the IMC possessed a higher cage temperature (females-1st restraint: 23.7 °C; 2nd restraint: 23.5 °C; males-1st restraint: 23.3 °C; 2nd restraint: 23.5 °C) compared with the TMC (females-1st restraint: 22.4 °C; 2nd restraint: 22.5 °C; males-1st restraint: 22.6 °C; 2nd restraint: 22.4 °C). The concentration of fecal corticosterone metabolites in the TMC (females-1st restraint: 1376 ng/g dry weight (DW); 2nd restraint: 2098 ng/g DW; males-1st restraint: 1030 ng/g DW; 2nd restraint: 1163 ng/g DW) was higher compared to control cage housing (females-1st restraint: 640 ng/g DW; 2nd restraint: 941 ng/g DW; males-1st restraint: 504 ng/g DW; 2nd restraint: 537 ng/g DW). Our results show the stress potential induced by metabolic cage restraint that is markedly influenced by the lower housing temperature. The IMC represents a first attempt to target cold stress reduction during metabolic cage application thereby producing more animal welfare friendlydata.

Assessing high resolution thermal monitoring of complex intertidal environments from space: The case of ECOSTRESS at Rias Baixas, NW Iberia

Currently, thermal sensors on satellites and other orbital platforms with high spatial resolution designed to monitor the oceans are often insufficient to assess the surface temperature of small bodies of water or within the coastal boundary layer. As the accuracy and sensitivity of remote sensing satellites improve, the demand for more accurate and up-to-date basic data sets for calibration increases. The quality of the thermal data collected by ECOSTRESS on the International Space Station allows the characterization of thermal stress levels in coastal ecosystems with a high spatial resolution of 70 m and a return time from hours to 5 days. This study focused on the calibration of ECOSTRESS estimates with in situ surface temperature data from sensors installed at 3 cm depth in the sediment on the intertidal muddy sandflats of three of the Rías Baixas in Galicia, NW Iberian Peninsula, from 2019 to 2021. A final number of 45 ECOSTRESS temperature images were analyzed. From these, 20% contained substantial georeferencing errors which had to be corrected manually with GIS software tools. We applied the Fourier's law of Heat Conduction to derive surface estimates from loggers sub-surface measurements that could be directly compared with ECOSTRESS data. Overall, a good calibration which explained more than 80% of ECOSTRESS temperature estimates for the whole dataset was obtained, but with an intrinsic cold bias around 1.39 °C. When temperatures at a depth of 3 cm were used, the linear fit became worse and the negative bias increased to 1.49 °C. Closer inspection revealed that night measurements were responsible for this larger deviation, as ECOSTRESS estimates became much colder compared to within sediment measurements because of the combined effect of the instrument intrinsic bias and nocturnal surface cooling. The best calibration was obtained when surface estimates were calculated just for the nighttime, as the cold bias decreased to 0.93 °C. More importantly, during hot daytime conditions in emersion above 20 °C, ECOSTRESS data matched surface temperature estimates, probably because of a better performance of ECOSTRESS algorithm at dry surfaces with lower emissivity. Thus, during the most ecologically relevant periods when high temperatures could drive thermal stress in many commercially-important bivalve species, ECOSTRESS provides accurate surface estimates that can be used to derive sub surface temperatures at the depths at which the different burrowing organisms live. We thus conclude that this instrument constitutes an important global tool to examine thermal stress at an unprecedented spatial scale for complex sea-land boundary systems.

Characterization of Thermal Patterns Using Infrared Thermography and Thermolytic Responses of Cattle Reared in Three Different Systems during the Transition Period in the Eastern Amazon, Brazil.

In the Lower Amazon mesoregion, there are basically three types of production systems: the traditional (without shade and no bathing area), the silvopastoral (with shade and no bathing area), and the integrated (with shade and bathing area). It is considered that the type of production system influences the thermal comfort and productivity of cattle, so this research aims to evaluate the influence of these three types of production systems on the thermoregulation of Nellore cattle. The experiment was carried out on a rural property for raising cattle, located in Mojuí dos Campos, Pará, Brazil, during the transition period (June/July). Thirty bovine males (not castrated, aged between 18 and 20 months, average weight of 250 ± 36 kg, body condition score of 3.5, clinically healthy) were randomly divided into three groups: Silvopastoral System-SS (n = 10), Traditional System-TS (n = 10), and Integrated System-IS (n = 10). Climate variables were collected (air temperature (AT °C), relative humidity (RH %), wind speed (WS, m/s), solar radiation (SR), black globe temperature (BGT °C), and physiological parameters, such as respiratory rate (RR) and rectal temperature (RT)) at 6 a.m., 12 p.m., 6 p.m., and 12 a.m. to determine the thermal comfort situation of the animals. Thermographic images of the environment and animals were captured in order to obtain the body surface temperature (BST) through infrared thermography. The Benezra Thermal Comfort Index (BTCI), Environmental Stress Index (ESI), Equivalent Temperature Index (ETI), and Iberian Heat Tolerance Index (Iberian HTI) were used. The results showed that the silvopastoral system, with shading by chestnut trees and an ample vegetative area, presented better thermal conditions, with an average of 28.98 °C, in comparison with the traditional system (35.93 °C) and the integrated one (34.11 °C). It was observed that the body surface temperature of cattle did not differ significantly between the anatomical regions of the body and the studied systems (p > 0.05). As for the respiratory rate, the traditional system registered higher values, with an average of 41 movements per minute, indicating possible thermal stress (p < 0.05). The thermal comfort indices revealed that all systems presented moderate stress conditions during times of higher solar intensity. It is concluded that the silvopastoral system proved to be more favorable for cattle, providing shade and reducing thermal stress, which may have a positive impact on animal welfare and productivity in this region.

Comparative measurements of surface body temperature of horses using infrared thermography

Infrared thermography is a painless, non-invasive method that can be used to improve the physiological assessment and health of the horse, and as an alternative, or in combination with other imaging methods and diagnostic procedures. The main advantage of thermography is the detection of subclinical signs of inflammation before the onset of clinical signs of pathology. The aim of this pilot study was to determine the surface body temperature of six clinically healthy horses in indoor conditions. The horses` bodies were laterally scanned on the left and right sides and were divided into the following regions: neck, shoulder, thoracic limb, back, thigh and pelvic limb. The abdominal region of the horses was scanned individually in ventral projection. The average temperature of each region was calculated. An approximately equal thermal symmetry was observed between both sides of the horse’s body.

Graphene-Based Wearable Temperature Sensors: A Review.

Flexible sensing electronics have received extensive attention for their potential applications in wearable human health monitoring and care systems. Given that the normal physiological activities of the human body are primarily based on a relatively constant body temperature, real-time monitoring of body surface temperature using temperature sensors is one of the most intuitive and effective methods to understand physical conditions. With its outstanding electrical, mechanical, and thermal properties, graphene emerges as a promising candidate for the development of flexible and wearable temperature sensors. In this review, the recent progress of graphene-based wearable temperature sensors is summarized, including material preparation, working principle, performance index, classification, and related applications. Finally, the challenges and future research emphasis in this field are put forward. This review provides important guidance for designing novel and intelligent wearable temperature-sensing systems.

Surviving heat: Resilience of Nellore bulls to solar radiation exposure

Surviving heat: Resilience of Nellore bulls to solar radiation exposure

Impact of Heat Stress on Blood, Production, and Physiological Indicators in Heat-Tolerant and Heat-Sensitive Dairy Cows.

Heat stress affects production and health in cows severely. Since it is difficult to define heat-tolerant animals, studies of response to heat stress are important for understanding dairy cows' health and production. However, information on the impact of heat stress on various indicators in heat-tolerant and heat-sensitive cows is sparse. This study aimed to investigate the effects of heat stress (HS) on blood, production, and physiological indicators in heat-tolerant and heat-sensitive cows. A total of 43 dairy cows were used from 9 May to 7 August 2021, under Temperature-Humidity Index (THI) measurements that ranged from 65.9 to 86.7. We identified cows that were tolerant or sensitive to HS based on the slope of the response of physiological and production traits against THI during the HS period by using a clustering method. After HS, serum glucose (Glu), cortisol (COR), 5-hydroxytryptamine (5-HT), and interleukin-6 (IL-6) levels of cows in the heat-tolerant group were lower than in the heat-sensitive group (p < 0.05). With THI as the predictor, the R2 for predicting respiration rate (RR) and body surface temperature (BT) in heat-tolerant cows was 0.15 and 0.16, respectively, whereas the R2 for predicting RR and BT in heat-sensitive cows was 0.19 and 0.18, respectively. There were low to moderate, positive correlations between RR, BT, and MY with THI, with Pearson correlation coefficients ranging from r = 0.11 to 0.4 in the heat-tolerant group, and from r = 0.24 to 0.43 in the heat-sensitive group. There was a low positive correlation between VT and THI, with a Spearman correlation coefficient of r = 0.07 in the heat-sensitive group. The heat-tolerant dairy cows had lower MY losses and had lower MY (p = 0.0007) in mixed models. Heat-tolerant cows with low-stress levels, through upregulating RR rapidly, increased their adaptability to thermal environments. They have better thermoregulation capability; the hypothalamic-pituitary-adrenal (HPA) axis regulated the thermoregulatory in animals by releasing a variety of neurotransmitters and hormones.

Clinical analysis of 66 cases of pseudo fever

Some patients who present with a "fever" may only have a localized increase in body surface temperature, while their core body temperature remains normal. This phenomenon is commonly referred to as pseudo fever. A retrospective analysis of clinical data from January 2013 to January 2020 at our fever clinic showed that 66 adolescents were diagnosed with pseudo fever. These patients typically showed a gradual increase in axillary temperature after their cold symptoms had disappeared. Most patients reported no significant complaints other than mild dizziness. Laboratory tests showed no significant abnormalities, and antipyretics were ineffective in lowering their body temperature. Pseudo fever is a relatively independent clinical phenomenon that is distinct from functional fever or simulated fever, and its underlying mechanism remains to be studied.