Computational insights into survival durations and prehospital interventions in accidental cold-water immersion: A comprehensive analysis of fresh and saltwater temperatures.

This study examines the complex relationship between scenarios of cold-water immersion, survival durations, and prehospital interventions. It utilizes computational modeling methods to shed light on how different water temperatures affect individuals facing accidental cold-water immersion incidents. The analysis reveals significant variations in survival times based on water temperature. For example, subjects immersed in water at temperatures of 5 °C, 2 °C, and 0 °C had average survival times of 136, 113, and 100 min, respectively, under stable conditions. In flowing water at the same temperatures, survival times decreased to 119, 92, and 81 min, indicating the impact of water movement on cooling rates and survival durations. Likewise, individuals immersed in saltwater at temperatures of 5 °C, 2 °C, 0 °C, and -2 °C showed average survival times of 111, 88, 80, and 66 min, respectively, in static conditions. In flowing saltwater at the same temperatures, survival times decreased to 98, 74, 68, and 57 min, highlighting the influence of water flow on cooling rates and survival durations. A comparison between immersion in pure water and saltwater at 2 °C revealed survival times of 113 and 88 min under stable conditions and 92 and 74 min under dynamic conditions, emphasizing the role of water composition in survival outcomes. The study also challenges the notion that the demise of the Titanic's passengers and crew resulted from hypothermia, asserting instead that severe thermal shock was the primary cause. These numerical findings underscore the importance of considering water temperature, flow dynamics, and prompt medical responses in cold-water emergencies to enhance survival prospects. The study identifies water within the range of 41-43 °C as the most effective active external rewarming fluid for critical hypothermal conditions. By quantifying the impact of these variables on survival times, the study provides data-driven recommendations to improve emergency protocols and outcomes for individuals facing cold-water immersion incidents.

Eye Temperature Measured with Infrared Thermography to Assess Stress Responses to Road Transport in Horses.

The aim of the present study was to investigate eye temperature modifications after road transport in athletic horses habituated to travel. Eight adult Italian saddle horses traveled 100 km and, two weeks later, 300 km. Eye temperature (ET), rectal temperature (RT) and serum cortisol concentration were assessed before (T1), after (T2) and 60 min (T3) after the road transport. ET was evaluated with infrared thermography (IRT) in three regions of interest: EL1 (medial canthus), EL2 (central cornea) and EL3 (lateral canthus). Two-way analysis of variance (ANOVA) for repeated measures showed statistically higher values at T2 and T3 for EL1 (p < 0.01), EL2 (p < 0.01) and EL3 (p < 0.01) following the 100 km journey. RT (p < 0.01) showed higher values at T2 and T3 after the 100 km journey and higher values at T2 (p < 0.01) following the 300 km journey. ET values were positively correlated with RT at T1, T2 and T3 following the 100 km journey and at T2 following the 300 km journey and positively correlated with serum cortisol concentration at T1, T2 and T3 following the 100 km journey and at T2 and T3 following the 300 km journey. Eye temperature monitoring with IRT allows quick and practical strategies to monitor an animal's physiological state and welfare during daily activities.

Effect of Heat Stress on Subsequent Estrous Cycles Induced by PGF2α in Cross-Bred Holstein Dairy Cows.

This study aimed to determine the effect of heat stress (HS) on reproductive parameters (calving to first service (CTFS) and the first-service conception rate (FSCR)) and general physiological responses (rectal temperature (RT) and respiratory rate (RR)) in tropical cross-bred Holstein dairy cows raised in Ratchaburi province, Thailand. HS was determined using the temperature-humidity index (THI), calculated from temperature and humidity inside the barns, and was classified as moderate HS (THI: 80.67 ± 0.79) and mild HS (THI: 77.81 ± 1.09) in this study. Cows with detected corpus luteum were defined as cyclic cows and were injected with PGF2α at the beginning of the experimental period. Reproductive and physiological parameters were recorded. Cows showed significantly lower RT and RR in the mild HS group (38.47 ± 0.21 °C and 41.04 ± 4.55 bpm, respectively) than in the moderate HS group (38.87 ± 0.15 °C and 51.17 ± 10.52 bpm). The percentage of cows that ovulated after being induced by PGF2α and showed estrus signs was higher in the mild than the moderate HS groups (54.55% vs. 18.18%). Furthermore, the FSCR of cows under mild HS tended to be higher than that in the moderate HS group (42.11% and 15%, respectively) (p = 0.06), while the average CTFS interval was significantly shorter under mild HS than moderate HS (69.47 ± 18.18 and 84.60 ± 27.68 days, respectively). These results indicate that moderate HS impairs reproductive performance in crossbred Holstein cows, compared to mild HS conditions.

Evaluation of a heating protocol and stocking density impact on heatstressed fattening pigs.

As climate change intensifies, heat stress mitigation for pigs becomes more important. Trials involving induced heat waves are useful to test several measures (e.g. reduced stocking density) at a faster rate, but only when accurately evaluated and validated. In the present study, we investigated the suitability of an artificial heating protocol at different pig weights (experiment 1). The impact of different stocking densities on fattening pigs during an artificial heat wave (experiment 2) was also investigated. Experiment 1: Forty 20-week-old pigs weighing 96.5 ± 7.3 kg (W100) and forty 17-week-old pigs weighing 72.7 ± 9.9 kg (W70) were housed in two compartments. An artificial heat wave (heat load) was induced for 3 days. During 3-day periods before, during and after the heat load, physiological parameters (respiration rate (RR), rectal temperature (Trectal), skin temperature (Tskin) and behavior) were measured and average daily feed intake was observed. Ambient temperature, relative humidity and temperature-humidity index (THI) were monitored. Experiment 2: A total of 150 fattening pigs were randomly divided into three treatment groups: SD1.3 (1.3 m2/pig), SD1.0 (1.0 m2/pig) and SD0.8 (0.8 m2/pig). All pens had a total pen surface of 4.88 m2, corresponding with 4, 5 and 6 fattening pigs in the SD1.3, SD1.0 and SD0.8 groups, respectively. The heat load was induced for 7 days on week 21. Respiration rate and Trectal were observed as in experiment 1. Average daily gain and average daily feed intake were also noted. During the heat load, THI reached ≥ 75 (78.4 (experiment 1) and 78.6 (experiment 2)), even when relative humidity decreased to ± 45%. Every physiological parameter showed significant increases during the heat load. The prolonged heating protocol in experiment 2 also provoked significant decreases in average daily feed intake (15%) and average daily gain (19%) for all groups. Weight within the studied range of 70-100 kg did not have a significant impact on any of the parameters. However, Tskin was affected by both weight and heat load (P < 0.05), where Tskin from W100 was always lower in comparison to W70. In addition, we found that 0.8 m2/pig doubled the increase of Trectal during the heat load, namely SD0.8 (0.22 °C) compared to SD1.0 (0.12 °C) (P = 0.033) and SD1.3 (0.13 °C) (P = 0.053). This suggests that pigs housed at higher densities are less able to regulate their internal heat production. However, RR and performances were not significantly affected by heat load in this experimental set-up. A stocking density of 1.0 m2/animal may be sufficient to mitigate some negative effects of heat stress.

Body Size, Cerebral Blood Flow, Ambient Temperature, and Relative Brain Temperatures in Newborn Infants under Incubator Care.

Subtle changes in body temperature affect the outcomes of ill newborns. However, the temperature profile of neonatal brains remains largely unknown. In open-cot care, increased cerebral perfusion is correlated with higher superficial brain temperatures. This study investigated the dependence of brain temperature (relative to rectal temperature) on ambient temperature, body size, cerebral perfusion, and metabolism in infants receiving incubator care. Rectal, scalp, and brain temperatures, superior vena cava flow, and brain oxygenation were assessed using echocardiography, thermo-compensatory temperature monitoring, and near-infrared spectroscopy in 60 newborns. These infants had a mean postconceptional age of 36.9 (2.2) weeks and weighed 2348 (609) g at the time of evaluation. The ambient temperature was maintained at 30.0 (1.0) °C. A higher rectal temperature was associated with greater postconceptional age (p = 0.002), body weight (p < 0.001), and head circumference (p < 0.001). Relative scalp, superficial brain, and deep brain temperatures were associated with smaller head circumference (p < 0.001, p = 0.030, and p = 0.015, respectively) and superior vena cava flow (p = 0.002, p = 0.003, and p = 0.003, respectively). In infants receiving incubator care, larger head sizes and increased brain perfusion were associated with lower relative scalp and brain temperatures. When considered alongside previous reports, cerebral perfusion may contribute to maintaining stable cerebral tissue temperature against ambient temperature changes.

Exertional Heatstroke Survivors' Knowledge and Beliefs about Exertional Heatstroke Diagnosis, Treatment, and Return to Play.

CONTEXT: Little information exists regarding what exertional heatstroke (EHS) survivors know and believe about EHS best practices. Understanding this would help clinicians focus educational efforts to ensure survival and safe return-to-play following EHS. OBJECTIVE: We sought to better understand what EHS survivors knew about EHS seriousness (e.g., lethality, short- and long-term effects), diagnosis and treatment procedures, and recovery. Design: Multi-year, cross-sectional, descriptive design. SETTING: An 11.3-km road race located in the Northeastern United States in August 2022 and 2023. PATIENTS OR OTHER PARTICIPANTS: Forty-two of 62 runners with EHS (15 women, 27 men; age: 33±15 y; pre-treatment rectal temperature [TREC]: 41.5±0.9°C). INTERVENTIONS: Medical professionals evaluated runners requiring medical attention at the finish line. If they observed TREC ≥40°C with concomitant central nervous system dysfunction (CNS) EHS was diagnosed and patients were immersed in a 189.3-L tub filled with ice-water. Before medical discharge, we asked EHS survivors 15 questions about their experience and knowledge of select EHS best practices. Survey items were piloted and validated by experts and laypersons a priori (content validity index ≥0.88 for items and scale). MAIN OUTCOME MEASURES: Survey responses. RESULTS: Sixty-seven percent (28/42) of patients identified EHS as potentially fatal and 76% (32/42) indicated it negatively affected health. Seventy-nine percent (33/42) correctly identified TREC as the best temperature site to diagnose EHS. Most patients (74%, 31/42) anticipated returning to normal exercise within 1 week post-EHS; 69% (29/42) stated EHS would not impact future race participation. Patients (69%, 29/42) indicated it was important to tell their primary care physician about their EHS. CONCLUSIONS: Our patients were knowledgeable on the potential seriousness and adverse health effects of EHS and the necessity of TREC for diagnosis. However, educational efforts should be directed towards helping patients understand safe recovery and return-to-play timelines following EHS.

Relationships of infrared thermography temperature with core temperature in goat.

Rectal temperature is widely used as an indicator of animal health. However, rectal temperature is conventionally measured by an invasive method, which may reduce animal welfare. So, this study aimed to determine the relationships between the deep-body (core) temperature and body surface temperatures in goats and develop a linear regression equation to establish the core temperature based on body surface temperatures. Body surface temperatures (head, eye, muzzle, horn, back, scrotum and groin) of goats were measured by infrared thermography (IRT). Ambient temperatures were measured by digital thermometer. Core temperatures were measured by a digital vet thermometer. Pearson correlation analysis was used to analyze the relationship between body surface temperatures, ambient temperature, and core temperature. Simple linear regression analysis was used to develop core temperature assessment equations. Correlation analysis showed that groin temperature was highly correlated with core temperature, and low correlated with ambient temperature. The body surface temperature of other region was low correlated with core temperature, and highly correlated with ambient temperature. Regression analysis showed that the determination coefficient of core temperature assessment equation based on groin temperature was the highest (P < 0.0001, R2 = 0.55), and those based on surface temperature of other regions were low (P < 0.01, R2 ≤ 0.16). We concluded that body surface temperatures obtained by IRT could be used for the assessment of goat core temperature. The core temperature assessment equations developed by the temperature of the body surface, which is less affected by ambient temperature, was found to have a higher determination coefficient than the equations developed using body surface temperature that is more affected by ambient temperature.

Effect of Simultaneous Dietary Supplementation of Betaine, Selenomethionine, and Vitamins E and C under Summer Conditions in Growing-Finishing Pigs.

Heat stress in pigs negatively affects welfare, health, and performance. Osmoprotectants and antioxidants may alleviate oxidative damage during hot periods. We investigated whether an additive-enriched feed can reduce negative effects in pigs during summer conditions. Sixty growing-finishing pigs were allocated into two groups: the control (CF) and summer feed (SF) group. The CF group contained 0.4 mg/kg inorganic selenium and 100 ppm vitamin E, while the SF group contained 0.3 mg/kg inorganic selenium, 0.1 mg/kg selenomethionine, 200 ppm vitamins E and C, and 0.2% betaine. Feed was offered ad libitum. Respiration rate, rectal and skin temperature, behaviour, and weight gain were assessed weekly. Daily measurements of these parameters were performed during a 3-day heat wave (temperature humidity index (THI) ≥ 75) and during an artificial heating period. Individual average daily water intake (ADWI) and feed intake were measured using RFID systems. The ADWI of the SF group did not change during heat load while it increased for the CF group. Independent of dietary treatment, increases in ∆THI or the THI were accompanied by significant increases in both respiration rate and skin temperature. In conclusion, the SF may induce a reduced need to increase ADWI during hot periods. In addition, mainly skin temperatures and especially respiration rates revealed the sensitivity of pigs to heat stress.

Hypothermia, anemia, hyperglycemia, and severe hypoglycemia are significant prognostic indicators of death in client-owned ferrets (Mustela putorius furo).

OBJECTIVE: To determine whether rectal temperature, Hct, or blood glucose at presentation were associated with all-cause mortality in ferrets (Mustela putorius furo). ANIMALS: 321 client-owned ferrets. METHODS: A medical record database was searched for ferrets from January 2012 through September 2022. Records from 1,189 individual examinations were evaluated. Inclusion criteria were rectal temperature, Hct, and/or blood glucose measured at presentation and data on survival status 7 days postpresentation. Data were included from 321 ferrets from 571 examinations. Rectal temperature in 244 ferrets from 346 examinations, Hct in 181 ferrets from 277 examinations, and blood glucose in 260 ferrets from 420 examinations were available. RESULTS: The odds of death for hypothermic ferrets (< 37.8 °C) were 3.72 times (OR, 3.72; 95% CI, 2.30 to 6.01) the odds of death for normothermic ferrets (37.8 to 40 °C). For every 0.56 °C below normal rectal temperature, the odds of death increased 1.49 times (OR, 1.49; 95% CI, 1.21 to 1.90). The odds of death for anemic ferrets (Hct < 33%) were 4.74 times (OR, 4.74; 95% CI, 1.70 to 13.21) the odds of death for ferrets with a normal Hct (33% to 57%). The odds of death for hyperglycemic ferrets (> 152 mg/dL) were 2.61 times (OR, 2.61; 95% CI, 1.29 to 5.30) the odds of death for normoglycemic ferrets (74 to 152 mg/dL). The odds of death for severely hypoglycemic ferrets (< 40 mg/dL) were 9.45 times (OR, 9.45; 95% CI, 3.18 to 28.12) the odds of death for normoglycemic ferrets. CLINICAL RELEVANCE: Hypothermia, anemia, hyperglycemia, and severe hypoglycemia were significant prognostic indicators of death in ferrets. Further investigation into the causes and management of these derangements is warranted.

A comparison of rectal versus fetlock temperatures in dorsally recumbent horses during general anesthesia.

OBJECTIVE: To investigate the effect of isoflurane anesthesia on thermoregulation and peripheral heat loss in dorsally recumbent horses. STUDY DESIGN: Prospective, clinical study. ANIMALS: Seven adult horses (2.6 ± 1.5 years old, 455 ± 70.2 kg). METHODS: Horses underwent elective surgical procedures in dorsal recumbency under general anesthesia (GA) maintained with isoflurane in oxygen. Rectal (TR), intranasal (TN) and fetlock surface temperatures (TF) were measured every 10 minutes for the first 80 minutes following induction of GA. Room temperature (TRO) was monitored during the study. Statistical analysis to determine differences between temperature measurement sites and techniques (TR, TN and TF), and differences over time were completed using a mixed-effects model with Tukey's multiple comparison or Dunnett's multiple comparison testing where appropriate. Significance was set at p < 0.05. RESULTS: Following induction of anesthesia, TF was significantly increased compared with baseline (0 minutes) from 40 to 80 minutes (p < 0.01). No significant differences were detected in TR and TN at any time point compared with baseline (p > 0.05). TF was significantly lower than TN (p < 0.02) at all time points and TR from times 0 to 70 minutes (p < 0.04). There were no significant differences between TR and TN at any time (p > 0.05). CONCLUSIONS: In horses undergoing isoflurane GA, TF increased, indicating peripheral heat loss likely because of vasodilation, whereas TR showed a clinically relevant decrease over time. These findings are suggestive of body heat redistribution during GA in horses in dorsal recumbency. Thermographic imaging of the peripheral limbs in combination with TR and TN monitoring allowed for recognition of peripheral heat redistribution in anesthetized horses. CLINICAL RELEVANCE: Anesthetized horses experience peripheral heat loss through their extremities as a result of vasodilation. Mitigating peripheral heat loss may improve thermoregulation and reduce hypothermic complications in anesthetized horses.

Hot water immersion is associated with higher thermal comfort than dry passive heating for a similar rise in rectal temperature and plasma interleukin-6 concentration.

PURPOSE: To compare the perceptual responses and interleukin-6 (IL-6) concentration following rectal temperature-matched dry heat exposure (DH) and hot water immersion (HWI). METHODS: Twelve healthy young adults (BMI 23.5 ± 3.6 kg/m2; age: 25.8 ± 5.7 years) underwent 3 trials in randomised order: DH (air temperature 68.9 °C), HWI (water temperature 37.5 °C), and thermoneutral dry exposure (CON, air temperature 27.3 °C). Blood samples to determine IL-6 plasma concentration were collected; basic affect and thermal comfort, rectal and skin temperature (Tskin) were assessed throughout the intervention. RESULTS: Rectal temperature (Trec) did not differ between DH (end temperature 38.0 ± 0.4 °C) and HWI (37.9 ± 0.2 °C, P = 0.16), but was higher compared with CON (37.0 ± 0.3 °C; P ≤ 0.004). Plasma IL-6 concentration was similar after DH (pre to post: 0.8 ± 0.5 to 1.4 ± 1.5 pg·ml-1) and HWI (0.5 ± 0.2 to 0.9 ± 0.6 pg·ml-1; P = 0.46), but higher compared with CON (0.6 ± 0.5 to 0.6 ± 0.4 pg·ml-1; P = 0.01). At the end of the intervention, basic affect and thermal comfort were most unfavourable during DH (Basic affect; DH: - 0.7 ± 2.9, HWI: 0.8 ± 1.9, CON 1.9 ± 1.9, P ≤ 0.004; Thermal comfort; 2.6 ± 0.8, HWI: 1.4 ± 0.9 and CON: 0.2 ± 0.4; P ≤ 0.004). Mean Tskin was highest for DH, followed by HWI, and lowest for CON (DH: 38.5 ± 1.3 °C, HWI: 36.2 ± 0.5 °C, CON: 31.6 ± 0.7 °C, P < 0.001). CONCLUSION: The IL-6 response did not differ between DH and HWI when matched for the elevation in Trec. However, thermal comfort was lower during DH compared to HWI, which may be related to the higher Tskin during DH.

Effects of heat stress on performance, physiological parameters, and blood profiles of early-fattening Hanwoo steers in climate chambers.

OBJECTIVE: This study was conducted to assess effects of heat stress on growth performance, physiological parameters, and blood profiles of Hanwoo steers during early-fattening period in climate chambers. METHODS: Four Hanwoo steers (body weight, 454.3±10.9 kg; age, 14±0.1 month) were allocated into four levels of temperature-humidity index (THI) in a 4×4 Latin square design for 21 days (pre-adaptation, 7 d; heat stress, 7 d; post-adaptation, 7 d) per period. Experimental treatments were assigned according to THI chart based on National Institute Animal Science (NIAS, 2022): Comfort (25.5°C to 26.5°C, 60%; THI 73 to 75), Mild (28°C to 29°C, 60%; THI 77 to 79), Moderate (29.5°C to 30.5°C, 80%; THI 82 to 84), and Severe (31°C to 32°C, 80%; THI 85 to 86) in separate climatic controlled chambers. RESULTS: The dry matter intake (DMI) of the formula feed was lower in Severe compared to Mild and Comfort (p<0.05). The DMI of rice straw was the lowest in Severe and lower in Moderate than Comfort and Mild (p<0.05). Both average daily gain and feed conversion ratio of Severe and Moderate were lower than those of Mild and Comfort (p<0.05). Water intake was the highest in Severe and lower in Moderate compared with Comfort and Mild (p<0.05). Heart rate and rectal temperature increased as THI level increased (p<0.05). Glucose was the lowest in Severe and lower in Moderate compared to Comfort (p<0.05). On the contrary, non-esterified fatty acid was the highest in Severe and lower in Moderate compared with Comfort (p<0.05). Blood urea nitrogen of Moderate and Severe were higher than those of Comfort and Mild (p<0.05). Cortisol increased as THI increased (p<0.05). CONCLUSION: This study demonstrated the negative effects of heat stress on the performance and physiological responses of Hanwoo steers during the early-fattening period. In addition, it is judged that the THI chart for Hanwoo steers of National Institute of Animal Science (2022) was properly calculated.

Can the inner eye canthus temperature be used as an alternative method to measure core temperature in sleep-deprived individuals?

Core temperature is used in several situations, including studies on biological rhythms and circadian markers of physical performance. Measuring the inner eye canthus (Tco) temperature is a method proposed to identify core temperature, but it has shown little concordance in physical exercise situations and has not yet been used in studies with measurements taken throughout the day. The objective of this study was to compare the measurements and daily behavior of Tco obtained by infrared thermography with rectal temperature (Tre) during a prolonged waking protocol. Eleven male individuals participated in the study, who remained in the laboratory for at least 38 h using an actigraph to determine the wakefulness time and were monitored during the entire period. The Tre and Tco measurements were performed every 3 h. The ANOVA was used for repeated measurements followed by Bonferroni's post-hoc test to find the limits of concordance/proximity, while the Bland and Altman method and the Intraclass Correlation Coefficient were used to establish the reliability between the pairs. The significance level adopted was p < 0.05. The results demonstrate significant differences, low levels of concordance and unsatisfactory reliability levels between Tco and Tre at all 13 analyzed moments, in addition to not showing measurement reliability when all data are used together with the 143 temperature measurements. Daily behavior analysis shows moments with similar behavior with an increase in Tco and Tre, but at other times the behavior was the opposite, with a decrease in one measurement and an increase in the other. Based on the results presented, it is not recommended to use the inner eye canthus temperature as a substitute for rectal temperature for measuring core temperature at different times of the day or in sleep-deprived individuals.

Non-invasive methods to quantify the carcass parameters of sheep: Interaction between thermal environment and residual feed intake.

The thermal environment is important in unit production because the perception of thermal stress can reduce fertility, and productive performance, therefore its management is necessary. The use of non-invasive methods, such as infrared thermography and real-time ultrasonography, are widely used to evaluate indicators in animal production, without the need to slaughter the animals. Thus, we aimed to assess the effect of the thermal environment on the physiological parameters and carcass characteristics of Dorper sheep with positive and negative residual feed intake (RFI) using infrared thermography and real-time ultrasonography techniques. Twenty uncastrated male Dorper sheep (17.8 ± 2.4 kg) were confined for 40 days for RFI classification. Sheep were separated into positive RFI (n = 10) and negative RFI (n = 10). The experimental design was in randomized blocks, in a 2 × 2 factorial arrangement, with 2 thermal environments (full sun or shade) and two feed efficiency groups (positive RFI or negative RFI), with 5 replications. The sheep remained in confinement for 60 days. The animals were slaughtered at the end of the experiment and the carcasses dissected for tissue separation. Rectal temperature (RT) and respiratory rate (RR) were measured at two times (14:00 h and 18:00 h) for periods of 5 days. The RR was determined by indirect auscultation of heart sounds at the level of the laryngotracheal region. The RT was measured introduced a digital clinical thermometer into the animal's rectum. Surface temperature (ST) was obtained using a thermographic infrared camera, collecting the temperatures of the eyeball and skin surface in the regions of the head, ribs, rump, flank and shin. Sheep confined in full sun showed higher RR (P = 0.0001), ST ribs (P = 0.0020), ST rumb (P = 0.0055), ST flank (P = 0.0001) and heat tolerance coefficient (HTC) (P = 0.0010). For sheep confined in full sun, a strong correlation was observed between the RR and the mean ST (MST; r = 0.6826; P = 0.0236) and between the final loin eye area (LEAf) with the real LEA (LEAr) (r = 0.9263; P = 0.0001) and slaughter body weight (SBW) (r = 0.7532; P = 0.0325). For negative RFI sheep, a positive correlation was observed between the RR and the ST rump (r = 0.7343; P = 0.0025) and ST ribs (r = 0.6560; P = 0.0178) and the MST (r = 0.7435; P = 0.0001), between the MST and the LEAr (r = 0.6837; P = 0.0025) and the final LEA (r = 0.6771; P = 0.0144), and between the final LEA and LEAr (r = 0.9942; P = 0.0001), BW (r = 0.8415; P = 0.0277) and MST (r = 0.6771; P = 0.0045). Positive RFI sheep confined to shade showed a high correlation between final LEA and LEAr (r = 0.9372; P = 0.0001). The use of shading in confined Dorper sheep, regardless of the RFI classification, reduces the effects of heat stress on physiological parameters.

Comparative study of antipyretic potency of extracts of morinda lucida leaves and fruits of capsicum frutescens in albino rats.

Background: Morinda lucida leaves and fruits of Capsicum frutescens are used locally in the management of fever in Nigeria. No scientific credence has been lent to this claim. Objective: To investigate the antipyretic effect and potency of aqueous extracts of Morinda lucida leaves and fruits of Capsicum frutescens in albino rats. Method: Brewer's yeast was used to induce pyrexia. Thirty animals were divided into six groups. Group A was orally administered normal saline (103 mg/kg). Group B was served indomethacin (5 mg/kg), while groups C and D received aqueous extract of Capsicum frutescens at 100mg/kg and 200mg/kg, 17 hours post induction of pyrexia. Groups E and F were administered extract of Morinda lucida at the same doses. Rectal temperature of the animals was taken at 60-, 90- and 120-minutes post-treatment. Results: Both C. frutescens and M. lucida produced significant reduction (p<0.05) in rectal temperature after 120 minutes in the rats compared with animals in the control group. Also, the antipyretic activities of the two extracts at 100mg/kg and 200mg/kg were comparable to 5mg/kg of indomethacin, with apparent dose dependence in the antipyretic activities of both extracts. Conclusion: Morinda lucida leaves and fruits of Capsicum frutescens exhibit dose-dependent antipyretic activities.

Effects of simulated high altitude on body temperature and heart rate in pilot reserves during the hot-dry exposure.

Recent research has primarily focused on human thermoregulatory responses at high altitudes, but investigations involving extremely high-temperature and hypobaric compound environments are currently lacking. To address this gap in knowledge, this study aimed to enhance the prediction of human heat sensation for pilot reserves while operating in extremely hot cabins with decompression. To achieve this, an improved Predicted Heat Strain (PHS) model was developed by incorporating the influence of air pressure on metabolic rate. The model's validity was assessed through experiments conducted at different altitudes (0m, 5000m, and 8000m) and varying environmental conditions (26°C and 45 °C, 10% RH and 40% RH) within an environmental simulation cabin. During these experiments, local skin temperature, core temperature, heart rate, and blood oxygen saturation were measured. The findings revealed distinct variations in the skin temperature of the hand and foot segments across different experimental stages, and significant correlations were observed between heart rate, core temperature, and local skin temperatures. Furthermore, regression models were established to explore the relationship between heart rate and local skin temperatures. By comparing simulated and experimental core and local skin temperatures, the enhanced PHS model was successfully validated. The conclusions drawn from this study provide valuable insights for predicting thermal physiological indices accurately and conveniently in hot-dry and hypobaric environments.

The use of body surface temperatures in assessing thermal status of hutch-reared dairy calves in shaded and unshaded conditions.

The study was carried out in a Hungarian large-scale dairy farm during a 5-day period in hot August weather. Altogether 16 preweaning calves were chosen for the study. An agricultural mesh with 80% shielding was stretched over eight calf cages at 2 m from the ground to shield the cages in their entirety, while eight others were left unshaded. Ambient temperature and relative humidity were measured in 10 min intervals inside and outside one of the hutches in the shaded and unshaded groups during the total length of the study. The rectal temperature of the calves was measured by a digital thermometer every 4 h. Surface temperatures were measured on body parts, in the same intervals as rectal temperature with an infrared thermometer. Measuring sites included: the leg (metacarpus), muzzle, eye bulb, scapula, and ear. Statistical analyses were performed to assess the effects of shading on environmental and body temperatures and to also assess the strength of the association between core, skin and ambient temperatures; to estimate the temperature gradient between body shell and core; to compare the changes in heat dissipation capacity of the different body regions (as represented by temperatures of various sites) with increasing ambient temperature controlling for shaded or unshaded conditions; and to predict the risk of hyperthermia (rectal temperature not lower than 39.5°C) with the CART classification method. The average rectal temperatures suggest that the temperature conditions both in shaded and unshaded groups imposed a severe heat load on the calves. The temperature of the body shell, as represented by skin temperatures, shows a much more significant variation, similar to ambient temperature. As expected, areas that are closer to the core of the body (ear and eye) show less difference from rectal temperature and show a narrower range (lower variance), as more distal regions (leg, scapula) have a wider range. Body surface temperatures are more related to ambient temperature in calves than rectal temperature. The predictive value of infrared body surface temperatures for predicting heat stress or rectal temperature is low.

An observational field study of porcine post-weaning diarrhea: clinical and microbiological findings, and fecal pH-measurements as a potential diagnostic tool.

BACKGROUND: Recently, in-feed medicinal zinc has been phased out in pig production in the European Union. This makes updated knowledge about porcine post-weaning diarrhea (PWD) crucial. The objectives of the present study were to investigate (i) the clinical presentation of PWD in pigs housed in Danish herds that did not use medicinal zinc, specifically the prevalence of diarrhea and whether PWD was associated to clinical signs of dehydration or altered body temperature; (ii) which microorganism are associated to PWD; and iii) whether measurements of the fecal pH have a potential to be used diagnostically to differentiate between infectious etiologies in cases of PWD. RESULTS: The prevalence of diarrhea varied considerably between the outbreaks in the nine studied herds (median = 0.58, range = 0.10; 0.94). In a cross-sectional design (n = 923), diarrhea was associated with reduced rectal temperature and alkaline feces. Diarrhea was also associated with observably reduced skin elasticity, possibly indicating dehydration. In both diarrheic case pigs (n = 87) and control pigs (n = 86), the presence of Brachyspira pilosicoli, Clostridium perfringens, Cryptosporidium spp., Cystoisopora suis, enterotoxigenic Escherichia coli, Lawsonia intracellularis, porcine circovirus types 2 and 3, rotavirus A, B, C, and H, Samonella enterica spp. enterica, and Trichuris suis was described. PWD was associated with high levels of enterotoxigenic E. coli shedding (odds ratio versus no E. coli detection = 4.79 [CI 1.14; 12.62]). Diarrhea was associated with high levels of rotavirus A shedding (odds ratio versus no/low rotavirus A = 3.80 [CI 1.33; 7.97]). The association between microbiological findings in diarrheic pigs and fecal pH was negligible. CONCLUSIONS: Enterotoxigenic E. coli was confirmed to be a cause of PWD; however, cases of PWD where enterotoxigenic E. coli was not detected in high levels occurred commonly, and this adds to the increasing evidence suggesting that PWD is not necessarily a result of enteric colibacillosis. Rotaviral enteritis might be a differential diagnosis of PWD. pH-measurements cannot be used to differentiate between differential diagnoses for PWD.

Could the different estrus periods significantly affect body temperature on clinical examination in bitches?

Clinical examination is essential to make a differential diagnosis list, and body temperature measurement is an indispensable part of the clinical examination. Throughout the estrus cycle, body temperature may fluctuate high enough to affect the clinical examination results. Aim of this study, whether there were any differences between the different estrus periods, body parts (rectal, intravaginal and corneal), and methods (contact thermography and infrared thermography) in regard to temperature in bitches. The animal material of this study consisted of 61 healthy, non-pregnant, non-sportive bitches (2.78 ± 0.22 mean years of age; mean weight 23.81 ± 1.61kg) of different breeds. Corneal temperature measurement results were found the least constant and significant differences were observed between different estrus periods except in the anestrus period. Rectal temperature (RT) measurement results were the most constant. However, in ANOVA analysis, significant differences were observed between the different estrus periods, and the difference between the anestrus and diestrus periods was very close to 0.5 °C. Although, in the Bland-Altman plot analysis, the agreement was observed only between rectal and intravaginal temperature (p: 0.572, r2: 0.70), the limits of agreement were not clinically acceptable. In conclusion, neither corneal temperature measurement with infrared technology nor intravaginal temperature measurement should not be an alternative to RT measurement, and RT measurement results should evaluate carefully considering the estrus period.

Investigation of post mortem brain, rectal and forehead temperature relations.

It is well known that magnetic resonance (MR) imaging is temperature sensitive, which is highly relevant for post mortem examinations. Therefore, the determination of the exact temperature of the investigated body site, e.g. the brain, is crucial. However, direct temperature measurements are invasive and inconvenient. Thus, in view of post mortem MR imaging of the brain, this study aims at investigating the relation between the brain and the forehead temperature for modelling the brain temperature based on the non-invasive forehead temperature. In addition, the brain temperature will be compared to the rectal temperature. Brain temperature profiles measured in the longitudinal fissure between the brain hemispheres, as well as rectal and forehead temperature profiles of 16 deceased were acquired continuously. Linear mixed, linear, quadratic and cubic models were fitted to the relation between the longitudinal fissure and the forehead and between the longitudinal fissure and the rectal temperature, respectively. Highest adjusted R2 values were found between the longitudinal fissure and the forehead temperature, as well as between the longitudinal fissure and the rectal temperature using a linear mixed model including the sex, environmental temperature and humidity as fixed effects. The results indicate that the forehead, as well as the rectal temperature, can be used to model the brain temperature measured in the longitudinal fissure. Comparable fit results were observed for the longitudinal fissure-forehead temperature relation and for the longitudinal fissure-rectal temperature relation. Combined with the fact that the forehead temperature overcomes the problem of measurement invasiveness, the results suggest using the forehead temperature for modelling the brain temperature in the longitudinal fissure.