Mathematical Simulation and Numerical Computation of the Temperature Profiles in the Peripherals of Human Brain during the Tepid Sponge Treatment to Fever.

BACKGROUND: Fever is one of the frequently occurring diseases in human beings, and the body is said to have befallen in fever if the arterial or internal body temperature rises to 38°C. The patient who suffers from fever is either given paracetamol or tepid sponging or both. OBJECTIVE: This paper is aimed at studying the effects of the tepid sponge in normalizing the high temperature of the human body during fever. Among the various available methods for tepid sponging, the impact of holding a cool wet cloth on the forehead for reducing the fever is analyzed and pictured graphically. METHOD: For analyzing the effects of tepid sponge on the temperature distribution of the domain consisting of scalp, skull, and cerebrospinal fluid (CSF), a cool wet cloth is brought in contact with the skin allowing the heat to transfer from the brain to the wet cloth through these layers. The heat transfer in living biological tissues is different from ordinary heat transfer in other nonliving materials. Therefore, a model based on the bioheat equation has been constructed. The model has been solved by numerical methods for both steady- and unsteady-state cases. The domain, which consists of the scalp, skull, and CSF layers of the human head, has been discretized into four equal parts along the axes of the three-dimensional coordinate system. The forward difference and forward time centered space approximations were employed for numerical temperature distribution results at the nodal points. RESULTS: The effects of tepid sponge in reducing the body temperature with fever at 38°C, 39.5°C, and 41°C have been numerically calculated, and the results were pictured graphically. For transient cases, the corresponding calculations have been carried out at times t = 2 minutes, 4 minutes, and 6 minutes. CONCLUSION: Among all the available remedies to fever, tepid sponging has shown a significant effect in controlling fever.

Regarding pandemics: Ibn Jatima from Almería anticipates the physiopathological concept of multi-organ failure in the 14th century.

In 1348, a pandemic known as Black Death devastated humanity and changed social, economic and geopolitical world order, as is the current case with SARS-CoV-2 coronavirus. The doctor of the Nasrid Kingdom of Granada, Ibn-Jatima from Almeria, wrote "Treatise on the Plague", in which it may be found epidemiological and clinical similarities between both plagues. In the context of Greco-Arab medicine, he discovered respiratory and contact contagion of Pestis and attributed its physiopathology to a lack of pulmonary cooling of the innate heat, generated in the heart and carried by the blood humor. The process described was equivalent to the oxygen transport system. Furthermore, it was supposed to generate toxic residues, such as free radicals, leading to an irreversible multiple organ failure (MOF), considered a mortality factor as in Covid-19. Due to its similitude, it would be the first antecedent of the MOF physiopathological concept, a finding that enriches the scientific and historical heritage of our clinical specialty.

Is vitamin D deficiency a risk factor for COVID-19 in children?

OBJECTIVE: Coronavirus disease 2019 (COVID-19) is a global health problem that can result in serious complications. The aim of this study was to investigate the prevalence and clinical importance of vitamin D deficiency in children with COVID-19. MATERIAL AND METHODS: This study includes 40 patients who were diagnosed to have COVID-19 and hospitalized with the real-time reverse transcription polymerase chain reaction method, 45 healthy matched control subjects with vitamin D levels. The age of admission, clinical and laboratory data, and 25-hydroxycholecalciferol (25-OHD) levels were recorded. Those with vitamin D levels which are below 20 ng/ml were determined as Group 1 and those with ≥20 ng/ml as Group 2. RESULTS: Patients with COVID-19 had significantly lower vitamin D levels 13.14 µg/L (4.19-69.28) than did the controls 34.81 (3.8-77.42) µg/L (p < .001). Patients with COVID-19 also had significantly lower serum phosphorus (4.09 ± 0.73 vs. 5.06 ± 0.93 vs. (U/L) (p < .001)) values compared with the controls. The symptom of fever was significantly higher in COVID- 19 patients who had deficient and insufficient vitamin D levels than in patients who had sufficient vitamin D levels (p = .038). There was a negative correlation found between fever symptom and vitamin D level (r = -0.358, p = .023). CONCLUSION: This is the first to evaluate vitamin D levels and its relationship with clinical findings in pediatric patients with COVID-19. Our results suggest that vitamin D values may be associated with the occurrence and management of the COVID-19 disease by modulating the immunological mechanism to the virus in the pediatric population.

Xuebijing injection in the treatment of COVID-19: a retrospective case-control study.

BACKGROUND: Neither a vaccine nor specific therapeutic drugs against 2019 novel coronavirus have been developed. Some studies have shown that Xuebijing injection (XBJ) can exert an anti-inflammatory effect by inhibiting the production of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and other cytokines. This study aimed to investigate the effect of XBJ on coronavirus disease 2019 (COVID-19) and its effects on IL-6 and tumor necrosis alpha TNF-α. METHODS: A total of 42 patients, who were diagnosed with COVID-19 and treated with XBJ combined with routine treatment at Chongqing University Three Gorges Hospital between January 20, 2020, and March 11, 2020, were selected as the observation group. A control group comprising 16 patients who received routine treatment was also established, and cases were matched from the observation group on a 1:1 basis according to age, comorbidities, and mild and severe disease. The clinical symptoms, laboratory test indexes, and changes in computed tomography (CT) scans of patients in the two groups were observed at the time of admission and 7 days after treatment, and the time taken for the patients to produce a negative nucleic acid test was also recorded. RESULTS: There were no significant differences in baseline data between the two groups. After treatment, there were significant improvements in IL-6 levels and body temperature in the observation group as compared with the control group. Particularly in severe patients, the reduction in body temperature in the observation group was greater than that in the control group (P<0.05). A higher number of patients in the observation group showed improved CT imaging results compared with the control group, and the time taken to produce a negative nucleic acid test was shorter in the observation group than in the control group; however, the differences were not statistically significant (P>0.05). Furthermore, there were no significant differences in TNF-α and IL-10 between the two groups. CONCLUSIONS: The results of this study suggest that routine treatment combined with XBJ can better improve the clinical outcomes of COVID-19 patients.

Epidemiology and clinical characteristics of 43 COVID-19 patients in Weifang, China.

BACKGROUND: To investigate the epidemiology and clinical characteristics of patients infected with coronavirus disease 2019 (COVID-19) in Weifang, China. METHODS: The demographic data of 43 COVID-19 patients identified in Weifang were used to investigate whether they had traveled to epidemic areas and whether they had close contact with confirmed cases. On admission, patients' symptoms and results of laboratory tests and imaging were analyzed. RESULTS: Among the 43 COVID-19 patients. including 9 third generation infected cases, 16 (37.2%) were imported, who infected the rest. Most cases were middle-aged with approximate sex ratio. A "super spreader", Mr. Zhang made it necessary to quarantine 69 medical personnel. Mr. Zhang directly infected six individuals who, in turn, infected another six individuals. Another patient, Mr. Wang, spread the infection to his five family members at a family gathering. Subsequently, the daughter infected her husband. The most common COVID-19 symptoms were fever, weakness, dry cough, and cough sputum. In most patients, white blood cell counts were not elevated and lymphocyte counts were decreased. Elevated C-reactive protein and serum amyloid A protein (SAA) levels were commonly observed. There was no death among the patients or infection among the medical staff. CONCLUSIONS: The infection by the COVID-19 in Weifang was mostly the result of close contact with imported cases. These circumstances underscore the need to comprehensively strengthen the management for patients to prevent and control the spread of the virus.

Antiinflammatory properties of antiLy6G antibody disappear during magnetic field exposure in rats with carrageenan induced acute paw inflammation.

Antiinflammatory properties of pulsed magnetic field (PMF) treatments or administration of antiLy6G antibody have been previously reported. In this study, we hypothesized that, the combination of PMF treatments and antiLy6G administration may synergistically potentiate their antiinflammatory actions. The effects of the combination of PMF treatments and antiLy6G administration were investigated by examining the inflammatory signs, histopathological properties of the inflamed site, and measuring the macrophage inflammatory protein-1 alpha (MIP-1α/CCL3) and myeloperoxidase (MPO) levels of inflamed paw tissues in rats with carrageenan-induced acute paw inflammation. In this present study, PMF treatments alone or administration of antiLy6G alone ameliorated the acute inflammation. However, their combination exacerbated the inflammatory signs, hyperalgesia, allodynia, edema and fever, and aggravated the inflammatory conditions by excessive infiltration of inflammatory cells to the inflamed site. These opposing effects of the combined treatments may correlate with enhanced levels of MIP-1α and MPO in inflamed paws. Present results indicated that the combination of the PMF treatments and antiLy6G administration may not provide additional benefits and may actually cause an aggravation of the acute inflammatory process. Findings may also suggest that during neutrophil or immune cell-targeted treatments for inflammatory states, magnetic field exposure may cause unexpected negative consequences.

Pharmacological evaluation of analgesic, anti-inflammatory and antipyretic activities of ethanolic extract of Indigofera argentea Burm. f.

ETHNOPHARMACOLOGICAL RELEVANCE: Indigofera argentea Burm. f.; commonly known as neel, jantari, hathio; is traditionally used for the treatment of headache, fever, inflammation and body pain. Local communities also used this plant for the treatment of malaria, jaundice, vertigo and gastric disorders. AIM OF THE STUDY: This study is aimed to evaluate the toxicity and possible analgesic, anti-inflammatory and antipyretic activities of the ethanolic crude extract of Indigofera argentea (IaCr) to support its use in folk medicine and to screen the phytochemical constituents and antioxidant activity. MATERIALS AND METHODS: Aqueous ethanolic (30:70) extract of whole plant of Indigofera argentea (IaCr) was prepared and phytochemical study was performed by preliminary methods followed by HPLC and DPPH method. In vivo experiments were performed in Wistar albino rats including hot plate, tail immersion, formalin and capsaicin-induced pain tests in rats and acetic acid-induced writhing test in mice. Anti-inflammatory activity was assessed by using in vitro human red blood cell (HRBC) membrane stabilization and carrageenan-induced rat paw edema test, while antipyretic activity was evaluated by Brewer's yeast-induced pyrexia test. RESULTS: The crude extract of Indigofera argentea confirmed the presence of flavonoids, glycosides, alkaloids, saponins and tannins as soluble ethanolic constituents in preliminary study. The maximum quantity of gallic acid equivalent (GAE) phenolics, and quercetin equivalent (QE) flavonoid content found was 81 ± 2 mg GAE/g and 56 ± 1.4 mg QE/g of extract respectively. Quantification based on HPLC exposed the presence of phenols and flavonoids, quercetin, gallic acid, caffeic acid, chlorogenic acid, benzoic acid, ferulic acid and coumaric acid. In vivo experiments revealed significant P < 0.05) dose-dependent inhibition in hot plate, tail immersion and capsaicin-induced pain test. IaCr showed significant inhibition of pain latency against both phases in formalin test and considerably decreased the number of writhes caused by acetic acid at the doses of 30, 100 and 300 mg/kg. In the in vitro anti-inflammatory (HRBC) assay, IaCr showed good membrane stability with maximum percentage hemolysis inhibition of 49.29% while in carrageenan-induced paw edema test in rats the IaCr showed significant anti-inflammatory action in a dose-dependent fashion. Statistical significant reduction in rectal temperature was observed at the doses of 100 and 300 mg/kg in yeast-induced pyrexia test in rats. CONCLUSION: The results of the experimental studies proved the analgesic, anti-inflammatory and antipyretic activities of Indigofera argentea and supported the traditional use of this plant.

Clinical features and treatment of COVID-19 patients in northeast Chongqing.

The outbreak of the novel coronavirus in China (SARS-CoV-2) that began in December 2019 presents a significant and urgent threat to global health. This study was conducted to provide the international community with a deeper understanding of this new infectious disease. Epidemiological, clinical features, laboratory findings, radiological characteristics, treatment, and clinical outcomes of 135 patients in northeast Chongqing were collected and analyzed in this study. A total of 135 hospitalized patients with COVID-19 were enrolled. The median age was 47 years (interquartile range, 36-55), and there was no significant gender difference (53.3% men). The majority of patients had contact with people from the Wuhan area. Forty-three (31.9%) patients had underlying disease, primarily hypertension (13 [9.6%]), diabetes (12 [8.9%]), cardiovascular disease (7 [5.2%]), and malignancy (4 [3.0%]). Common symptoms included fever (120 [88.9%]), cough (102 [76.5%]), and fatigue (44 [32.5%]). Chest computed tomography scans showed bilateral patchy shadows or ground glass opacity in the lungs of all the patients. All patients received antiviral therapy (135 [100%]) (Kaletra and interferon were both used), antibacterial therapy (59 [43.7%]), and corticosteroids (36 [26.7%]). In addition, many patients received traditional Chinese medicine (TCM) (124 [91.8%]). It is suggested that patients should receive Kaletra early and should be treated by a combination of Western and Chinese medicines. Compared to the mild cases, the severe ones had lower lymphocyte counts and higher plasma levels of Pt, APTT, d-dimer, lactate dehydrogenase, PCT, ALB, C-reactive protein, and aspartate aminotransferase. This study demonstrates the clinic features and therapies of 135 COVID-19 patients. Kaletra and TCM played an important role in the treatment of the viral pneumonia. Further studies are required to explore the role of Kaletra and TCM in the treatment of COVID-19.

Hyperthermia, positive feedback loop with IL-6 and risk of NSCLC progression: a tangle to unravel?

Fever may represent a risk factor for NSCLC by increasing IL-6 expression. In this light, an accurate and rapid control of fever among lung cancer patients should be carefully added to the treatment plan. On this regard, concerns increase when doubts arise regarding the applicability of hyperthermia on NSCLC given the potential interaction of IL-6 with NSCLC. Thus, I suggest that randomized, controlled double-arm clinical studies are warranted for an evidence-based evaluation of feasibility of the hyperthermia application in the management of NSCLC.

Effect of thermal preconditioning on Hsp70 expression in the medulla oblongata and on hemodynamics during passive hyperthermia.

A short-term episode of elevated core body temperature that induces Hsp70 expression (thermal preconditioning) may protect against heatstroke during subsequent hyperthermia. The protective effects of thermal preconditioning may involve several cellular and immunological mechanisms and improvements in baroreflex sensitivity. To substantiate the hypothesis that the protective effect of thermal preconditioning also occurs in conditions with intact thermoregulation, we examined the evolution of spontaneous cardiovagal baroreflex sensitivity and the protective effect of Hsp70 expression after thermal preconditioning in nonanesthetized Wistar-Kyoto rats with implanted telemetric transmitters. In the baroreflex centers of the medulla oblongata, thermal preconditioning induced Hsp70 in perineuronal and perivascular oligodendrocytes, microglia, and endothelial cells but not in neurons. The maximal Hsp70 expression was detected 4 h after preconditioning, but a significant number of Hsp70-positive cells was still present 72 h after preconditioning. Increased c-Fos expression in the neurons of baroreflex centers was detectable only 4 h after preconditioning. The mean values of cardiovagal baroreflex sensitivity did not show significant differences during the 72-hour follow-up period after thermal preconditioning. Similarly, cardiovascular variability measures of the autonomic nervous system activity were also not significantly affected by thermal preconditioning. During passive hyperthermia, thermal preconditioning had no statistically significant effect on thermoregulation and the onset of arterial pressure decline. Our data suggest that thermal preconditioning induces a glial type of Hsp70 expression in the baroreflex centers of the medulla oblongata. However, this response was not associated with cardiovagal baroreflex sensitization and protection against hemodynamic instability during passive hyperthermia.

Current applications of fecal microbiota transplantation in intestinal disorders.

Fecal microbiota transplantation (FMT) had been an ancient remedy for severe illness several centuries ago. Under modern medical analysis and evidence-based research, it has been proved as an alternative treatment for recurrent Clostridium difficile infection and recent randomized control study also showed that FMT could be an adjuvant treatment for inflammatory bowel disease. As we get a better understanding of the relationship between gut microbiota and systemic disease, FMT became a potential treatment to explore. This article summarized procedures such as donor selection, fecal material preparation, transplantation delivery methods, and adverse events. We also review the present evidence about FMT in clinical practice.

Complete Clinical Remission of Stage IV Triple-Negative Breast Cancer Lung Metastasis Administering Low-Dose Immune Checkpoint Blockade in Combination With Hyperthermia and Interleukin-2.

The prognosis of triple-negative breast cancer with metastases after chemotherapy remains dismal. We report the case of a 50-year-old female with first disease recurrence at the axillary lymph node and, later on, bilateral pulmonary metastases with severe shortness of breath. The patient received low-dose immune checkpoint blockade (concurrent nivolumab and ipilimumab) weekly over 3 weeks with regional hyperthermia 3 times a week, followed by systemic fever-range hyperthermia induced by interleukin-2 for 5 days. She went into complete remission of her pulmonary metastases with transient WHO I-II diarrhea and skin rash. The patient remained alive for 27 months after the start of treatment, with recurrence of metastases as a sternal mass, and up to 3 cm pleural metastases. This exceptional response should instigate further research efforts with this protocol, which consists only of approved drugs and treatments.

The Phytochemical and Biological Investigation of Jatropha pelargoniifolia Root Native to the Kingdom of Saudi Arabia.

Extensive phytochemical analysis of different root fractions of Jatropha pelargoniifolia Courb. (Euphorbiaceae) has resulted in the isolation and identification of 22 secondary metabolites. 6-hydroxy-8-methoxycoumarin-7-O-ß-d-glycopyranoside (15) and 2-hydroxymethyl N-methyltryptamine (18) were isolated and identified as new compounds along with the known diterpenoid (1, 3, 4, and 7), triterpenoid (2 and 6), flavonoid (5, 11, 13, 14, and 16), coumarinolignan (8⁻10), coumarin (15), pyrimidine (12), indole (17, 18), and tyramine-derived molecules (19⁻22). The anti-inflammatory, analgesic, and antipyretic activities were evaluated for fifteen of the adequately available isolated compounds (1⁻6, 8⁻11, 13, 14, 16, 21, and 22). Seven (4, 6, 10, 5, 13, 16, and 22) of the tested compounds showed a significant analgesic effect ranging from 40% to 80% at 10 mg/kg in two in vivo models. Compound 1 could also prove its analgesic property (67.21%) when it was evaluated on a third in vivo model at the same dose. The in vitro anti-inflammatory activity was also recorded where all compounds showed the ability to scavenge nitric oxide (NO) radical in a dose-dependent manner. However, eight compounds (1, 4, 5, 6, 10, 13, 16, and 22) out of the fifteen tested compounds exhibited considerable in vivo anti-inflammatory activity which reached 64.91% for compound 10 at a dose of 10 mg/kg. Moreover, the tested compounds exhibited an antipyretic effect in a yeast-induced hyperthermia in mice. The activity was found to be highly pronounced with compounds 1, 5, 6, 10, 13, and 16 which decreased the rectal temperature to about 37 °C after 2 h of the induced hyperthermia (~39 °C) at a dose of 10 mg/kg. This study could provide scientific evidence for the traditional use of J. pelargoniifolia as an anti-inflammatory, analgesic, and antipyretic.

A Glutamatergic Hypothalamomedullary Circuit Mediates Thermogenesis, but Not Heat Conservation, during Stress-Induced Hyperthermia.

Stress elicits a variety of autonomic responses, including hyperthermia (stress fever) in humans and animals. In this present study, we investigated the circuit basis for thermogenesis and heat conservation during this response. We first demonstrated the glutamatergic identity of the dorsal hypothalamic area (DHAVglut2) neurons that innervate the raphe pallidus nucleus (RPa) to regulate core temperature (Tc) and mediate stress-induced hyperthermia. Then, using chemogenetic and optogenetic methods to manipulate this hypothalamomedullary circuit, we found that activation of DHAVglut2 neurons potently drove an increase in Tc, but surprisingly, stress-induced hyperthermia was only reduced by about one-third when they were inhibited. Further investigation showed that DHAVglut2 neurons activate brown adipose tissue (BAT) but do not cause vasoconstriction, instead allowing reflex tail artery vasodilation as a response to BAT-induced hyperthermia. Retrograde rabies virus tracing revealed projections from DHAVglut2 neurons to RPaVglut3, but not to RPaGABA neurons, and identified a set of inputs to DHAVglut2 → RPa neurons that are likely to mediate BAT activation. The dissociation of the DHAVglut2 thermogenic pathway from the thermoregulatory vasoconstriction (heat-conserving) pathway may explain stress flushing (skin vasodilation but a feeling of being too hot) during stressful times.

Physical characteristics cannot be used to predict cooling time using cold-water immersion as a treatment for exertional hyperthermia.

We examined if physical characteristics could be used to predict cooling time during cold water immersion (CWI, 2 °C) following exertional hyperthermia (rectal temperature ≥39.5 °C) in a physically heterogeneous group of men and women (n = 62). Lean body mass was the only significant predictor of cooling time following CWI (R2 = 0.137; P < 0.001); however, that prediction did not provide the precision (mean residual square error: 3.18 ± 2.28 min) required to act as a safe alternative to rectal temperature measurements.

[THE DIFFERENTIATED APPROACH TO PREVENTION OF NEURAL TUBE DEFECTS IN CHILDREN].

Neural tube defects occupy second place in frequency after the defects of the cardiovascular system. The folate metabolism violation and hyperhomocysteinemia in women are proved to be the leading risk factors for the NTD of the fetus. Polymorphism of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR) is a genetic determinant of folate metabolism violation. Admission of folic acid in a standard dose of 0.4 mg and / or the use of fortified foods does not allow reaching the protective level of folic acid if there is a mutation of the MTHFR gene or when several risk factors combine, which requires a higher dose of folic acid. The aim of the study is to develop an algorithm for the identification of women of reproductive age with the risk of having a child with NTD and to apply differentiated approach to the choice of a preventive dose of folic acid. A retrospective analysis of NTD cases in the Odessa region (Ukraine) for 2000-2013 was carried out. The frequency of the birth of children with CNS defects and NTD, risk factors of NTD in children were studied. Mothers and their children with NTD were evaluated for the level of folic acid, homocysteine and the presence of C677T and A1298C MTHFR polymorphisms. The incidence of spina bifida aperta is 4.9 per 10,000 newborns. Two groups of significant risk factors for the NTD in children were identified: 1) risk factors that can be eliminated - the absence of preconceptional prevention of NTD with folic acid (AR 0.4), second-hand tobacсo smoking (AR 0.33), fever/hot baths in the first trimester of pregnancy (AR 0.64), use of well water for cooking (AP 0.44); 2) risk factors that can not be eliminated, and which indicate a genetic risk of NTD - a family history of a stroke, heart attack, thrombosis, congenital malformations, malignant tumors (AR 0.54-0.7), an obstetrical history of miscarriage (AR 0.56 ), mother's diseases (varicose disease, obesity), NTD in other children in this family (AR 0.74). The mothers of children with NTD showed a decreased level of folic acid and an increased level of homocysteine in addition to the correlation of hyperhomocysteinemia with the mutations of the MTHFR gene. The algorithm for assessing the individual risk of having a child with NTD includes the evaluation of risk factors. If a genetic factor of folate metabolism violation or environmental risk factors that can not be eliminated are found, we recommend an additional examination. It includes determining the level of homocysteine and the MTHFR polymorphisms (in the case of hyperhomocysteinemia), which will identify the required dose of folic acid.

Patient With Unresectable Cholangiocarcinoma Treated With Radiofrequency Hyperthermia in Combination With Chemotherapy: A Case Report.

Hyperthermia, which is a noninvasive treatment that causes tumor cells to become heated and that works in synergy with anticancer drugs and radiation therapy, is emerging as a promising treatment for patients with cancer. The purpose of this study is to report the efficacy of hyperthermia combined with chemotherapy (gemcitabine/cisplatin) for the treatment of a patient with unresectable cholangiocarcinoma. A 54-year-old man was diagnosed as hilar cholangiocarcinoma (Klatskin tumor) and was administered neoadjuvant and preoperative radiation with chemotherapy. However, because the treatment with radiation and chemotherapy was not successful, he decided to undergo hyperthermia combined with chemotherapy as a second treatment option. He was suffering from fatigue, dyspepsia, epigastralgia, and jaundice. Hyperthermia combined with chemotherapy was administered 32 times over a period of 4 months. The patient experienced no critical complications, and the patient's condition improved, with the carbohydrate antigen 19-9 (CA 19-9) and the total bilirubin levels being relatively lowered. In addition, the computed tomography scan showed that the cholangiocarcinoma had not progressed. In conclusion, this case report suggests radiofrequency hyperthermia combined with chemotherapy may be a promising treatment option for patients with unresectable cholangiocarcinoma.

Hyperthermia-induced Neural Alterations Impair Proprioception and Balance.

PURPOSE: Hyperthermia has been shown to affect both central and peripheral nervous systems. However, the consequences of these alterations on the proprioceptive mechanisms underlying human movement control remain unclear. The aim of this study was to investigate the effect of passive hyperthermia on various measures of proprioception and balance, two key components of injury prevention and movement efficiency. METHODS: After a familiarization session, 14 volunteers (8 males, 6 females) completed two experimental sessions in temperate (CON, 24°C) and hot (HOT, 44°C-50°C) conditions, in a counterbalanced order. Participants were tested for neural function (electrically evoked M-wave and Hoffman reflex, Soleus), active movement discrimination (five positions, 50 trials, dorsiflexion), dynamic balance (Star Excursion Balance Test, three directions), and static balance (single-leg stance). RESULTS: Both rectal (39.0°C ± 0.3°C vs 36.9°C ± 0.6°C) and mean skin (37.9°C ± 1.0°C vs 32.0°C ± 2.7°C) temperatures were significantly higher in HOT than CON (P < 0.05). Hyperthermia significantly reduced the Hoffman reflex (P < 0.05) but not the M-wave (P > 0.05) amplitudes, increased the mean error for active movement discrimination (0.58°± 0.13° vs 0.50° ± 0.11°, +17%, P < 0.05), decreased the average distance reached in the posteromedial direction during dynamic balance (88.6 ± 7.9 cm vs 90.9 ± 6.1 cm, P < 0.05), and increased the contact area of the foot (126 ± 14 cm vs 122 ± 13 cm, +2.7%, P < 0.05) and the center of pressure excursion (64 ± 14 vs 57 ± 9 cm, +11.1%, P < 0.10) during single-leg stance. CONCLUSIONS: The current study suggests that hyperthermia impairs the proprioception and balance parameters measured. These observations might be due to heat-induced alterations in efferent and afferent signals to and from the muscle.