Skin Temperature Response Research Articles

Effect of different Volumes of exercise on skin temperature responses over the following 24 hours

Skin temperature responses have been advocated to indicate exercise-induced muscle soreness and recovery status. While the evidence is contradictory, we hypothesize that the presence of muscle damage and the time window of measurement are confounding factors in the skin temperature response. The objective was to determine whether skin temperature is influenced by different workloads and the time course of temperature measurements over the following 24 h. 24 trained male military were assigned to one of three groups: GC group (n = 8) serving as control not performing exercises, GE group (n = 8) performing a simulated military combat protocol in an exercise track with different obstacles but designed not to elicit muscle damage, and the GEMD group (n = 8) performing the simulated military combat protocol plus 5 sets of 20 drop jumps, with 10-sec between repetitions and with 2-min of rest between sets aiming to induce muscle damage. Skin temperature was measured using infrared thermography before exercise (Pre) and 4 (Post4h), 8 (Post8h) and 24h (Post24h) post-exercise. Perception of pain (DOMS) was evaluated Pre, Post24h, and Post48h, and countermovement jump height was evaluated at Pre and Post24h. DOMS did not differ between groups in the Pre and Post24h measures but GEMD presented higher DOMS than the other groups at Post48h (p < 0.001 and large effect size). Jump height did not differ for GEMD and GC, and GE presented higher jump height at Post24h than GC (p = 0.02 and large effect size). Skin temperature responses of GEMD and GG were similar in all measurement moments (p > 0.22), and GE presented higher skin temperature than the GC and the GEMD groups at Post24h (p < 0.01 and large effect sizes). In conclusion, although physical exercise elicits higher skin temperature that lasts up to 24 h following the efforts, muscle soreness depresses this response.

Experimental investigation on physiological and perceptual thermal responses through simulated hot-humid deep mine conditions

Miners in underground space often experience discomfort and heat strain due to combination of hot-humid environment and strenuous physical intensity. To investigate the impacts of manipulated variables, amounts of trials were conducted in a controlled climate chamber, with air temperatures of 29 °C and 32 °C, air velocities of 0.8 m/s and 1.8 m/s, and labor intensities of 3 km/h and 5 km/h, respectively. The physiological responses of mean skin temperature (Tmsk), oral temperature (Tor), sweat loss (SW), and heart rate (HR) were measured during these trials, along with the perceptual responses of thermal sensation vote, thermal comfort vote, thermal satisfaction vote, thermal acceptability vote, air movement expectation vote. The results indicate that Tmsk, Tor, SW and HR exhibit an upward trend in response to increasing air temperature and labor intensity, but decrease with rising air velocity. Tmsk and Tor are primarily affected by air temperature, while SW and HR are predominantly influenced by labor intensity. Notably, increased air temperature and labor intensity have negative effects on perceptual sensations, whereas augmentation in air velocity can marginally mitigate perceptual sensations. Tmsk and sweating rate exhibit the potential to serve as an indicator for evaluating and forecasting perceptual sensation. Tmsk values of 36 °C and 35 °C can be identified as the maximum thresholds for miners' thermally acceptable and comfortable skin temperatures. The findings can provide valuable references for understanding thermal responses of individuals in hot-humid deep mine conditions, and establish a robust basis for promoting working safety and comfort of miners.

Response of skin temperature, blood ammonia and lactate during incremental exercise until exhaustion in elite athletes

The study aimed to evaluate the lower limb skin temperature (Tsk) and blood concentrations of lactate (LA) and ammonia (NH3) during exercise and recovery. Eleven elite sprint athletes (25 ± 3.4 yrs) and 11 elite endurance athletes (24.45 ± 5.4 yrs) performed an incremental running test until exhaustion. Body composition was estimated using the DXA method. Thermograms of the anterior and posterior surfaces of the lower limbs were recorded at rest, before each test stage (every 3 min, starting from 10 km h−1 and increasing by 2 km h−1), and in the 5th, 10th, 15th, 20th, and 30th minute of recovery. Endurance athletes had a higher maximum oxygen uptake than sprint athletes (5.0 ± 0.7 vs 4.3 ± 0.4 l·kg−1, p = 0.018), lower percentage of lean content (79 ± 2 vs 83 ± 2%, p < 0.001), and a higher percentage of fat content in the lower limbs (17 ± 2 vs 12 ± 2%, p < 0.001). In both groups, a significant decrease in Tsk was observed compared to resting value (endurance athletes—31.5 ± 0.6 °C; sprint athletes—32.3 ± 0.6 °C), during exercise (p < 0.001) and rewarming during recovery (p < 0.001). However, endurance athletes had a lower Tsk than sprint athletes at the exhaustion point (30.0 ± 1.1 vs 31.6 ± 0.8 °C, p < 0.05) and the pattern of change in Tsk differed between groups (p < 0.001). Tsk in the endurance athletes group decreased throughout the exercise protocol and returned more rapidly to initial values during recovery, while Tsk in the sprint group stabilised between moderate intensity and exhaustion, recovering more slowly after exercise. Both LA (endurance athletes—max 10.2 ± 1.5; sprint athletes—max 10.1 ± 1.4 mmol⋅L−1, p < 0.001) and NH3 (endurance athletes—max 75.6 ± 11.5; sprint athletes—max 76.7 ± 9.0 mmol⋅L−1, p < 0.001) increased during exercise and decreased during recovery (p < 0.001). During exercise, lower levels and slower increases in LA were observed during exercise in the endurance athletes’ group (p < 0.05). A negative correlation was revealed between Tsk and fat percentage (r = −0.43 to −0.71, p < 0.05). Tsk was positively correlated with LA during recovery (r = 0.43 to 0.48, p < 0.05), and negatively during recovery (r = −0.45 to −0.54, p < 0.05). Differences between groups in maximum aerobic capacity, the pattern of change in Tsk, and the correlation between Tsk and LA suggest that individuals who decrease less Tsk during exercise and higher Tsk during recovery are those with better aerobic capacity. In addition, athletes with less body fat dissipate heat from their tissues more efficiently.

IGF-1, C-Reactive Protein, and Skin Temperature Responses to a Non-Contact Team Sport Activity Circuit in Under-20 Elite Soccer Players

IGF-1, C-Reactive Protein, and Skin Temperature Responses to a Non-Contact Team Sport Activity Circuit in Under-20 Elite Soccer Players

Порівняльний аналіз температурної реакції поверхні шкіри мошонки під час хірургічного лікування пацієнтів із патологією вагінального відростка очеревини різними способами

The vaginal peritoneal process pathology constitutes a widespread problem in the pediatric population. Pathology of the vaginal peritoneal process is 6 times more common among boys. The observations point out a possible array of male complications (scrotal edema, postoperative hydrocele, iatrogenic testicular refraction) occurring on the background of violation of the integrity of soft tissues, blood and lymphatic vessels. The analysis of local body reactions (namely, the temperature of the surface of the scrotal skin) in response to the pathology as well as its treatment was continued in the current study. Purpose - to detect the dynamic change of the scrotum skin surface temperature study with a view to comparing different methods of treating pathology of the vaginal peritoneal process. Materials and methods. The study included 122 boys under the age of 18 who have been treated for pathology of the vaginal peritoneal process (inguinal hernia, hydrocele testis) at the pediatric surgery clinic of National Pirogov Memorial Medical University, Vinnytsya, Ukraine. A VEGA NC600 non-contact infrared thermometer was used to measure the scrotal skin surface remotely on the day of hospitalisation, on the first postoperative day and on the seventh postoperative day. Results. The general dynamics of scrotal skin surface temperature, both on the pathological and healthy sides, are as follows: a slight increase in scrotal skin temperature in response to surgery is observed on the first postoperative day, followed by a subsequent decrease to preoperative levels. Conclusions. The study of the dynamic temperature changes of the scrotum skin surface in the case of correction of the vaginal peritoneal process pathology using various methods demonstrated that one of the local reactions of the body to the surgery was a slight increase of the average data on the side of the surgical intervention on the first day, followed by a decrease in the preoperative average level. A similar temperature response was recorded on the healthy side. The research was adhered to the principles of the Declaration of Helsinki. The research protocol was agreed by the Local Ethics Committee of the mentioned institution. The patients' informed consent was obtained for the study. No conflict of interests was declared by the authors.

ENDOCANNABINOID SYSTEM IN THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS MODULATES AUTONOMIC AND CARDIOVASCULAR CHANGES BUT NOT VASOPRESSIN RESPONSE IN A RAT HEMORRHAGIC SHOCK MODEL.

We evaluated the participation of the endocannabinoid system in the paraventricular nucleus of the hypothalamus (PVN) on the cardiovascular, autonomic, and plasma vasopressin (AVP) responses evoked by hemorrhagic shock in rats. For this, the PVN was bilaterally treated with either vehicle, the selective cannabinoid receptor type 1 antagonist AM251, the selective fatty acid amide hydrolase amide enzyme inhibitor URB597, the selective monoacylglycerol-lipase enzyme inhibitor JZL184, or the selective transient receptor potential vanilloid type 1 antagonist capsazepine. We evaluated changes on arterial pressure, heart rate, tail skin temperature (ST), and plasma AVP responses induced by bleeding, which started 10 min after PVN treatment. We observed that bilateral microinjection of AM251 into the PVN reduced the hypotension during the hemorrhage and prevented the return of blood pressure to baseline values in the posthemorrhagic period. Inhibition of local 2-arachidonoylglycerol metabolism by PVN treatment with JZL184 induced similar effects in relation to those observed in AM251-treated animals. Inhibition of local anandamide metabolism via PVN treatment with URB597 decreased the depressor effect and ST drop induced by the hemorrhagic stimulus. Bilateral microinjection of capsazepine mitigated the fall in blood pressure and ST. None of the PVN treatments altered the increased plasma concentration of AVP and tachycardia induced by hemorrhage. Taken together, present results suggest that endocannabinoid neurotransmission within the PVN plays a prominent role in cardiovascular and autonomic, but not neuroendocrine, responses evoked by hemorrhage.

Developing thermal prediction models for the elderly under temperature step changes

Daily transitions between indoor and outdoor environments involving temperature step changes have been extensively studied in young people, but little attention has been given to age-related differences and the development of thermal prediction models specifically for the elderly. To address this knowledge gap, a study was conducted in a climate chamber using warm-neutral-warm experimental sessions. Twenty-four elderly participants were selected from volunteers who met the health and body shape requirements. Thermal sensation vote (TSV) and mean skin temperature (MST) responses of the elderly were collected and analyzed. The results demonstrate that temperature step changes (3–9 °C) and neutral thermal experiences significantly influence the thermal responses of the elderly. Compared to the young, the elderly exhibit lower TSV, lower MST, lower skin heat loss, and different associations between TSV and skin heat loss. Leveraging these age-related differences, an MST prediction model was established for the elderly. The predicted MST can also serve as an input for the TSV prediction model established in this study. The TSV prediction model is based on skin heat loss and applicable to both transient and steady-state conditions. This study introduces a new approach for predicting the thermal responses of the elderly and enhances understanding of age-related differences in thermal responses.

Thermal resting pattern and acute skin temperature response to exercise in older adults: Role of cardiorespiratory fitness

BackgroundInfrared thermography is a growing area of interest in sports science due to the potential of skin temperature (Tsk) measurements to provide valuable information from rest to exercise. However, limited research exists on Tsk in older adults and the impact of factors such as sex and cardiorespiratory fitness (CRF) on Tsk. This study aims to investigate Tsk at rest and after acute exercise in older adults and assess whether sex or CRF influences Tsk. MethodsNinety-two participants (41 women, 68.48 ± 3.01 years) were examined with a thermographic camera in a conditioned room (23.02 ± 3.01 °C) at rest and after a graded protocol. The Tsk of 25 regions of interest (ROIs) were extracted and analysed. ResultsMen had higher overall Tsk at rest in 76% of ROIs, showing significant differences (p < 0.010) in six specific ROIs, independent of CRF. Both sexes had similar Tsk responses after graded exercise, with increases in distal parts (1.06 ± 0.50 °C), decreases in proximal parts (−0.62 ± 0.42 °C), and stable central Tsk (0.23 ± 0.59 °C). Increases in lower limb Tsk were significantly associated with CRF in men and women (β = 0.438, p = 0.001, and β = 0.535, p < 0.001, respectively), explaining 17% and 27% of the variance, respectively. ConclusionsThis study demonstrates a sex-specific effect on resting Tsk in older adults, suggesting that sex-specific Tsk patterns should be considered when analysing Tsk in this population. Additionally, the association between increases in lower limb Tsk and CRF suggests that Tsk could be a promising predictor of CRF in older adults.

Knee skin temperature response of patients with bilateral patellofemoral syndrome before and after heat and cold stress

Patellofemoral Pain Syndrome is characterized by the presence of pain in the front area of the knee, which occurs when performing common activities such as climbing stairs, and bending the knees, among others. The objective of this research was to evaluate the detection capability of infrared thermography in patients with Patellofemoral Pain Syndrome, in the baseline state, as well as after the application of thermal stress. The investigation was conducted in 48 patients, who were subdivided into four groups (n = 12). Two subgroups were healthy patients and two with Patellofemoral Pain Syndrome. For the diagnosis of the syndrome, a manual evaluation was performed using the Zohlen test and Q angle measurement. Subsequently, cold stress was applied for 10 min to a healthy subgroup and an experimental subgroup. The remaining two subgroups were subjected to heat stress for 15 min. Thermographic images of the lower extremities were acquired at seven time points, at baseline, immediately after application of thermal stress and then every 3 min until 15 min were completed. It was observed that patients presented Patellofemoral Pain Syndrome bilaterally. After statistical analysis, it was found that there were no significant differences in baseline temperature between the groups. However, for heat stress, a higher temperature was observed in the group with Patellofemoral Pain Syndrome (p < 0.05) in the recovery period, and in the case of cold stress, only a lower temperature in the left knee immediately after the application. In conclusion, it is not possible to detect patellofemoral syndrome bilaterally in the baseline state by thermography and neither is it evident in cold stress. However, after heat stress, thermal recovery is lower for the PFPS group, so it would be susceptible to detection.

Development of a 6 GHz RF-EMF Exposure System for Investigating Human Skin Temperature Responses: Characterization, Integration, and Pilot Testing

Development of a 6 GHz RF-EMF Exposure System for Investigating Human Skin Temperature Responses: Characterization, Integration, and Pilot Testing

Acute Mechanical and Skin Temperature Responses to Different Interrepetition Rest Intervals During Full-Squat Exercise.

This study aimed to (1)evaluate the acute effects of different interrepetition rest full-squat protocols on countermovement jump (CMJ) height, velocity loss (VL), and skin temperature (Tsk) and (2)determine whether the VL, the changes in Tsk, or the individual strength level is associated with the change in CMJ height. Sixteen resistance-trained men randomly performed 3 squat protocols at maximal intended velocity with 60% of the 1-repetition maximum (sets × repetitions [interrepetition rest]): traditional (2 × 6 [0s]), cluster 2 (2 × 6 [30s every 2 repetitions]), and cluster 1 (1 × 12; [36s every repetition]), plus a control session. CMJ height was assessed before and 2, 4, and 8minutes after the protocols. There was a significant main effect of protocol for the VL (F = 20.54, P < .001) and loss in mean power (F = 12.85, P < .001; traditional > cluster 2 > cluster 1). However, we found a comparable reduction of CMJ height after 8minutes: traditional (-3.4% [4.2%]), cluster 2 (-5.3% [4.9%]), cluster 1 (-5.4% [2.9%]), and control (-4.2% [3.6%]). Overall, mean Tsk acutely decreased after all the protocols. Higher individual strength level (but not VL or the changes in Tsk) was associated with lower CMJ-height loss (P < .05). Although different interrepetition rest full-squat protocols may alter the loss in velocity and power, they result in a similar decrease in Tsk and CMJ height, which could be more influenced by individual strength level than VL or changes in Tsk.

Evaluation of lidocaine for brachial plexus blockade in eastern box turtles (Terrapene carolina carolina)

ObjectiveTo evaluate latency and duration of a brachial plexus block technique in eastern box turtles performed with 2% lidocaine at three dose rates. Study designProspective, randomized, blinded crossover study. AnimalsAdult eastern box turtles, two for drug dose evaluation and a group of six (three male, three female) weighing 432 ± 40 g (mean ± standard deviation) for the main study. MethodsAnimals were randomly assigned to four brachial plexus blocks with lidocaine at 5, 10 and 20 mg kg–1 or 0.9% saline (treatments LID5, LID10, LID20 and CON, respectively), separated by 1 week. Treatment side was randomized and blocks were performed unilaterally. Baseline observations of mentation, heart rate (HR), respiratory rate (fR), skin temperature and limb response to manipulation or toe pinch were evaluated. Assessments were made every 10 minutes until 1 hour of normal sensory and motor function to the treated thoracic limb, or for a total of 2 hours if no block was evident. ResultsMotor and sensory blockade was achieved in treatments LID10 and LID20 in one turtle, with a latency of 10 minutes and duration of 50 minutes for both doses. Raising of the ipsilateral lower palpebra occurred with both blocks. Turtles administered lidocaine experienced higher HR compared with CON, and HR decreased over time for all individuals. Mentation and fR were not changed with any lidocaine dose. ConclusionsThe technique was unreliable in producing brachial plexus motor and sensory blockade at the lidocaine doses evaluated in this study. HR was higher in lidocaine-administered turtles but remained within normal limits for the species. No change in mentation or fR was observed among treatments. Clinical relevanceGeneral anesthesia with systemic analgesia is recommended for surgical procedures involving the chelonian thoracic limb. Further studies are needed to optimize a brachial plexus block in this species.

The Infrared Thermography Toolbox: An Open-access Semi-automated Segmentation Tool for Extracting Skin Temperatures in the Thoracic Region including Supraclavicular Brown Adipose Tissue

Infrared thermography (IRT) is widely used to assess skin temperature in response to physiological changes. Yet, it remains challenging to standardize skin temperature measurements over repeated datasets. We developed an open-access semi-automated segmentation tool (the IRT-toolbox) for measuring skin temperatures in the thoracic area to estimate supraclavicular brown adipose tissue (scBAT) activity, and compared it to manual segmentations. The IRT-toolbox, designed in Python, consisted of image pre-alignment and non-rigid image registration. The toolbox was tested using datasets of 10 individuals (BMI = 22.1 ± 2.1 kg/m2, age = 22.0 ± 3.7 years) who underwent two cooling procedures, yielding four images per individual. Regions of interest (ROIs) were delineated by two raters in the scBAT and deltoid areas on baseline images. The toolbox enabled direct transfer of baseline ROIs to the registered follow-up images. For comparison, both raters also manually drew ROIs in all follow-up images. Spatial ROI overlap between methods and raters was determined using the Dice coefficient. Mean bias and 95% limits of agreement in mean skin temperature between methods and raters were assessed using Bland–Altman analyses. ROI delineation time was four times faster with the IRT-toolbox (01:04 min) than with manual delineations (04:12 min). In both anatomical areas, there was a large variability in ROI placement between methods. Yet, relatively small skin temperature differences were found between methods (scBAT: 0.10 °C, 95%LoA[-0.13 to 0.33 °C] and deltoid: 0.05 °C, 95%LoA[-0.46 to 0.55 °C]). The variability in skin temperature between raters was comparable between methods. The IRT-toolbox enables faster ROI delineations, while maintaining inter-user reliability compared to manual delineations. (Trial registration number (ClinicalTrials.gov): NCT04406922, [May 29, 2020]).

Combining multiple human physiological signals using fuzzy logic to determine stress caused by battle dress uniforms

This study presents a novel stress index for clothing using physiological signals to estimate stress induced by battle dress uniforms (BDU) during physical activity. The approach uses a fuzzy logic-based nonlinear mapping to compute the stress from physiological signals. Ten healthy men performed a battery of physical activities in a controlled environment. Heart rate (HR), respiration rate (RR), skin temperature (ST), and galvanic skin response (GSR) were measured continuously for the participants during activity wearing three kinds of clothing (two BDUs and a control garment). The individual physiological responses were combined using a fuzzy-logic system to derive a stress measure called Clothed Activity Stress Index (CASI). Repeated measures ANOVA showed that the garments significantly (α = .05) affected the HR (p < .001) and RR (p < .001). In addition, interactions between the activity and garment were significant for HR, RR, and ST (p < .001, p < .001, p < .036). The physiological measures differed significantly between rest and activity for the two uniforms. The stress indices (ranging between 0 and 1) during rest and activity were 0.24 and 0.35 for control, 0.27 and 0.43 for BDU-1, and 0.33 and 0.44 for BDU-2. It is shown here that clothing systems impact human stress levels to a measurable level. This computational approach is applicable to measure stress caused by protective wear under different operational conditions and can be suitable for sports and combat gears.Article HighlightsA computational approach to non-linearly map human physiological signals and stress is presented.The stress caused by functional clothing systems is estimated using a fuzzy-logic mapping system for battle dress uniforms.Heart and respiration rates are highly sensitive to stress, while skin temperature and galvanic skin response are moderately sensitive.

Sex differences during a cold-stress test in normobaric and hypobaric hypoxia: A randomized controlled crossover study.

Cold and hypoxia are two stressors that are frequently combined and investigated in the scientific literature. Despite the growing literature regarding normobaric hypoxia (NH) and hypobaric hypoxia (HH), responses between females and males are less often evaluated. Therefore, this study aims to investigate the physiological sex differences following a cold-stress test under normoxia, normobaric- and hypobaric hypoxia. A total of n = 10 females (24.8 ± 5.1 years) and n = 10 males (30.3 ± 6.3 years) from a university population volunteered for this study. The cold-stress test (CST) of the right hand (15°C for 2 min) was performed using a randomised crossover design in normobaric normoxia, NH and HH. The change (∆) from baseline to post-CST up to 15 min was analysed for cutaneous vascular conductance (CVC) and the hands’ skin temperature, whilst the mean values across time (post-CST up to 15 min) were assessed for peripheral oxygen saturation (SpO2), thermal sensation- and comfort. Pressure pain threshold (PPT) was assessed after the post-CST 15 min period. The hands’ skin temperature drop was higher (p = 0.01) in the female group (∆3.3 ± 1.5°C) compared to the male group (∆1.9 ± 0.9°C) only in NH. Females (−0.9 ± 0.5) rated this temperature drop in NH to feel significantly colder (p = 0.02) compared to the males (−0.2 ± 0.7). No differences were observed between sexes in NN, NH, and HH for ∆CVC, SpO2, thermal comfort and PPT. In conclusion, females and males show similar reactions after a CST under normoxia and hypoxia. Sex differences were observed in the local skin temperature response and thermal sensation only in NH.

Infrared thermal imaging-based skin temperature response during cupping at two different negative pressures

Cupping therapy can relieve muscle fatigue and pain after exercise by increasing blood flow at the treatment site, which may lead to dynamic changes of the local skin temperature. This study aimed to analyze the effect of cupping on local skin temperature under two different negative pressures using infrared thermography (IRT). Cupping therapy was performed on the forearms of 22 healthy subjects using the negative pressures of − 0.03 and − 0.04 MPa. IRT was used to record the dynamic changes in skin temperature before, during, and after cupping. Both cupping pressures induced a non-linear skin temperature response: temperature decreased first and then increased during cupping, while it first increased and then decreased after cupping. A significant difference was noted between the two negative pressure groups in the maximum temperature increment after cupping (P < 0.001). Compared with the basal temperature before cupping, the maximum increase in skin temperature after cupping in the − 0.03 and − 0.04 MPa groups was 0.92 and 1.42 °C, respectively. The findings of this study can lay the foundation evaluating the curative effect of cupping based on IRT and provide an objective reference for selecting the cupping negative pressure.

Skin temperature response to thermal stimulus in patients with hyperhidrosis: A comparative study

Primary hyperhidrosis (HH), the excessive sweating exceeding physiological demand, has been associated to a complex dysfunction of the autonomic nervous system which may explain the disfunction in sweating but may also cause unrevealed alterations in skin blood flow regulation. In fact, HH patients present a sympathetic over-function with less reflex bradycardia in response to the Valsalva maneuver and higher sympathetic skin responses. We aimed to identify response patterns to room thermal stimulus in HH patients compared to a control group in order to investigate putative differences in blood flow assuming that skin temperature in glabrous (non-hairy) areas reflect the sympathetic tone in arteriovenous anastomoses (AVAs). Infrared thermography images were obtained from a cohort of patients diagnosed with HH, followed at a hospital pediatric surgical department and to a sex- and age-matched control group of patients admitted for other surgical procedures. With the participants in Fowler's position, a set of 3 images were captured simultaneously and 44 regions of interest were analyzed, distributed on the palms of the hands, soles of the feet, axilla, and inner canthus. After an acclimatization period at 20 °C, the room temperature was increased to 24, 28 and 32 °C to obtain similar sets of thermograms. A total of 37 patients with HH and 16 participants in the control group were included in the study. At baseline (20 °C), body core temperature (measured in the inner canthus) was significantly higher in the HH patients compared to the controls (p = 0.019 and p = 0.003 in right and left inner canthi, respectively), without any significant differences in the other thermograms. When room temperature was increased, differences in core temperature disappeared, while differences appeared in axilla and palms of the hands with HH patients presenting significantly lower temperature at the three thermal stimulus stages. Patients with HH presented a lower thermoregulatory response when submitted to room temperature increase, which may reflect a vasomotor sympathetic over-function in AVAs.

Relationship Between Skin Temperature Response And Metabolic Flexibility In Endurance Runners And Professional Soccer Players

During endurance exercise, skin temperature (Tsk) plays a fundamental role in thermoregulation and might be influenced by aerobic fitness (VO2peak) and metabolic flexibility, both powerful predictors of athletic performance. PURPOSE: The aim was to study the correlation between Tsk response and metabolic flexibility and stress by measuring blood lactate concentrations ([La-]), fat oxidation (FATox) and carbohydrate oxidation (CHOox) rates in highly trained (HT) competitive endurance runners, moderately active (MA) runners and professional soccer (PS) players. METHODS: we used indirect calorimetry, [La-] measurements, and monitored the Tsk response in HT (n = 22; VO2peak = 58.57 ± 2.33 ml/kg/min), MA (n = 20; VO2peak = 49.07 ± 4.67 ml/kg/min), and PS (n = 23; VO2peak = 53.34 ± 3.67 ml/kg/min) during an incremental maximal treadmill test (3-min intervals) until exhaustion, followed by a recovery period of five minutes. Descriptive were obtained for all variables. One-way ANOVA with post-hoc Bonferroni test were performed to compare the groups, and Pearson’s r correlation coefficients to assess the relationships among the variables studied. RESULTS: MA group exhibited lower VO2peak, Speedpeak, and higher BMI and fat mass % (all p < 0.05) than both HT and PS groups. Average FATox rates and Tsk were significantly higher in HT (0.30 ± 0.08 g.min-1; 35.55 ± 0.48 °C) and PS (0.23 ± 0.13 g.min-1; 35.62 ± 0.50 °C) compared with the MA (0.19 ± 0.11 g.min-1; 34.98 ± 0.50 °C) group, respectively (all p < 0.001). Significant correlations were found between [La-] and Tsk for each group (HT: r = 0.572; MA: r = 0.589; PS: r = 0.603), and there were correlations among the average [La-] and the average rates of FATox across the three groups studied (p < 0.05). CONCLUSIONS: These findings indicate that higher VO2peak and FATox rates and lower [La-] were associated with increased Tsk during incremental maximal exercise across individuals of widely different metabolic capabilities. Tsk seems to be a valid biomarker for metabolic fitness, as well as an attractive concept for the assessment and monitoring of athletes during competition. Furthermore, our data show significant differences which should be taken into account when developing individualized strategies for both nutrition and training in order to enhance athletic performance.

Assessment of thermal comfort of frail people in a sitting posture under non-uniform conditions using a thermal manikin

Thermal comfort has gradually become an important research field in the context of sustainable living. Several thermal comfort studies have been conducted in thermally uniform environments, though far fewer are being performed in non-uniform thermal conditions. Recently, the evaluation of thermal responses in non-uniform thermal environments, has come to the attention of researchers. This study aims to evaluate the thermal responses of frail people using a “Newton” thermal manikin and a test chamber. Personalized cooling and heating floor systems were used to produce non-uniform conditions by supplying global cooling air flow and vertical heat flow to the whole manikin body. In this paper, skin temperature, core temperature, and thermal responses were examined and discussed in both males and females. The analysis showed a significant difference in thermal sensation and dynamic thermal sensation between females and males over time, and under the same experimental conditions. On the other hand, the ANOVA analysis revealed a significant difference in the main effect of gender in terms of thermal comfort. Results show that thermal discomfort in frail people originated largely from air temperature. It was found that air temperature increments of 5 °C–30 °C can modify thermal comfort by 1.5 scale units’ in comparison with the thermal sensation.

Comparison of the effects of high and low levels of solar radiations on exercise capacity in hot outdoor environments.

High solar radiation from the sun in the heat outdoor may be impaired exercise capacity. This study aimed to compare the effects of different levels of solar radiation on exercise capacity and evaluate skin temperature responses in the heat. Seven male participants performed cycling exercise at 60% of their maximal oxygen uptake until volitional exhaustion in hot outdoor environments (approximately 33-35°C, 40-50% relative humidity) under both clear sky (high solar radiation trial: 1062±50 W/m2) and under thick clouds (low solar radiation trial: 438±52 W/m2). The time to exhaustion of the participants was shorter in the high solar radiation trial (32.0±12.4 min) than in the low solar radiation trial (39.2±18.0 min: P=0.045). Mean skin temperature was significantly higher in the high solar radiation trial than that in the low solar radiation trial (P<0.05); however, the rectal temperature did not differ significantly between the two trials. The high solar radiation trial had narrower core-to-skin temperature gradient, greater the body heat gain from the sun, and higher rating of perceived exertion than the low solar radiation trial. These results indicate that high solar radiation during outdoor exercise in the heat causes a greater increase in skin temperature and body heat gain from the sun than low solar radiation and consequently impairs exercise capacity.