Hand Skin Temperature Research Articles

The effect of exposure to cold on dexterity and temperature of the skin and hands

Objectives. This study aimed to determine the impact of low temperature (−1 °C, +5 °C) on manual dexterity and hand skin temperature after 1 h of exposure when using two types of protective gloves. Methods. Ten male participants wore double gloves or single gloves, when spending 1 h in a climatic chamber at −1, +5 or +20 °C. Before and after the cold exposure, measurements of mean weighted body skin temperature, hand skin temperature, the Purdue Pegboard Test and hand grip strength were performed. Results. There were statistically significant differences in the values of mean weighted body skin temperature and left and right hand skin temperature between the study variants. Conclusion. No effect of cold exposure (−1 °C, +5 °C) on manual dexterity was observed, but there was an effect of −1 °C temperature change on weighted mean skin temperature and hand skin temperature during 1 h of exposure. The decrease in both right and left hand skin temperature after cold exposure was the largest for −1 °C while using single gloves, and differed significantly from the other variants.

Physical management in algodystrophy syndrome

Aim: Complex regional pain syndrome (CRPS) is characterised by chronic pain, swelling, and vasomotor dysfunction. The disorder often gradually leads to muscle dystrophy, bone defects, and decreased limb function. The etiology of this condition has not been fully established. Aim. To analyse the physical therapy in CRPS patients treated at the Division of Physical Medicine of the Department of Rehabilitation in 2012-2022. Materials and Methods: The study involved a group of 58 patients after distal epiphyseal fractures of the forearm and crus. Testing concerned the following: hand or foot skin temperature, hand grip strength, pain intensity, bone radiographs, and psychosomatic profile according to Zung’s scale. Physical therapy included whirlpool massage, lidocaine and calcium iontophoresis, variable low frequency magnetic fields, and kinesiotherapy. Results: After 6-week treatment, we achieved full clinical improvement in 82% of the patients and partial improvement in 18% (these were patients in whom the treatment was introduced at an advanced stage of the disorder). Conclusions: 1. Complex regional pain syndrome is a difficult clinical problem. 2. Early diagnosis and introduction of focused physical therapy allow for full restoration of limb function.

Kaposiform hemangioendothelioma presented with raynaud phenomenon: a case report

BackgroundKaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm affecting infants or young children. KHE includes a spectrum of lesions, ranging from small and superficial tumors to large and invasive lesions with Kasabach-Merritt phenomenon (KMP). Currently, no published studies have reported a KHE presenting as thrombocytopenia and Raynaud phenomenon.Case presentationA 2-year-old boy with right hand swelling and thrombocytopenia was admitted to our hospital. His right hand turned swelling and red, even occasionally cyanotic. This condition became worse in response to cool environments and improved with warming, and platelet counts were between 50 ~ 80 × 10^9/L. Physical examination on admission revealed the swelling and frostbite-like rash of the right-hand fingers, and the skin temperature of the right hand was lower than the left. On day 3 of admission, chest CT results showed an irregular mass on the right side of the spine. The puncture biopsy demonstrated positive CD31, D2-40, and FLI1 immunohistochemical staining, but negative GLUT1 staining, confirming the diagnosis of KHE. Furthermore, endothelin-1 (ET1) expression levels significantly increased, and eNOS and A20 expression levels significantly decreased comparing with control patients. The patient received methylprednisolone and sirolimus treatments, and his condition gradually improved during the follow-up.ConclusionsWe reported the first case of KHE presenting with thrombocytopenia and Raynaud phenomenon. The development of Raynaud phenomenon could be associated with increased ET-1 and reduced eNOS and A20 expressions. Careful differential diagnosis of hidden KHE should be considered in children with thrombocytopenia and Raynaud phenomenon.

The Effect of Different Degrees of Cold Exposure on Medical Laypeople’s Tourniquet Application Time and Quality: A Within-Group Trial

Introduction:Cold exposure generally has a negative effect on tasks that rely on finger dexterity. It is not known if cold exposure will affect medical laypeople’s ability to perform first aid for life-threatening bleedings, specifically tourniquet application. This study investigates the effect of cold exposure on medical laypeople’s tourniquet application ability.Method:Twenty-nine adult medical laypersons received brief tourniquet application training and then completed a tourniquet application test in a baseline condition and three partial cold immersion conditions where their hands were immersed in nearly 0°C water. The three cold immersion conditions were 16°C, 12°C, and 8°C hand-skin temperature. Tourniquet application quality was measured using a procedural checklist. Time until bleeding control was also measured.Results:The results show that cold exposure significantly increases the time to bleeding control, F(3, 84) = 5.42, p < .01, η2 = .05. Planned contrasts revealed a significant increase in time between baseline and 8°C hand-skin temperature (M baseline = 65.5s, SD = 17.0; M 8°C = 76.9s, SD = 19.6), t(28) = 3.77, p < .01, r = 0.38. No effect was found on the procedural application quality, F(3, 84) = 2.21, p = .09.Conclusion:Cold exposure can decrease the chance of survival for the injured person when a medical layperson provides first aid for life-threatening bleedings due to increased application time. The results can also be used when educating medical laypeople in first aid for life-threatening bleedings as it provides evidence of specific effects from a stressor that is common in regions with cold climate. Future research should be aimed at exploring possible mitigation strategies such as tourniquet design or rewarming procedures and investigating if a similar effect exists for prehospital professionals.

손 냉각과 압박이 조합된 항암 치료용 장갑이 손의 혈관 수축 및 국소 감각에 미치는 영향

This study investigated the combined effects of wrist compression and hand cooling on cutaneous vasoconstriction of the hands to develop chemotherapy gloves that alleviate side-effects of anti-cancer treatments. Eight healthy young females (23 ± 3 y in age, 162 ± 4 cm in height, 60 ± 8 kg in weight, 22.6 ± 3.0 kg•mSUP-2/SUP in body mass index, 29.0 ± 6.6 % body fat) participated in the following three experimental conditions: cooling only with 14℃ (CO), cooling & intermittent compression (CIC), and cooling & continuous compression (CCC). The results showed 1) no significant differences in finger skin blood flow(%) or finger skin temperature among the three conditions, 2) no significant difference in hand skin temperature between the CO and CCC or CIC conditions, and 3) no significant differences in overall thermal sensation or thermal comfort among the three conditions. However, subjects felt more wrist and hand pressure and tingle sensations in the CIC (pressure phase) and CCC conditions than in the CO condition (P0.001). In conclusion, we did not find any synergistic effects on hand skin vasoconstriction from adding wrist compression to hand cooling, and the pressure and tingling sensations were deteriorated by adding the compression band. Therefore, we suggest cooling the hands at 14oC during cancer treatments, rather than adding compression with cooling.

We are all exposed, but some are more exposed than others

ABSTRACT This paper defines functional cold exposure zones that illustrate whether a person is at risk of developing physical performance loss or cold weather injuries. Individual variation in body characteristics, activity level, clothing and protective equipment all contribute to variation in the effective exposure. Nevertheless, with the right education, training, and cold-adapted behaviours the exposure differences might not necessarily lead to increased risk for cold injury. To support the preparation process for cold weather operations, this paper presents a biophysical analysis explaining how much cold exposure risk can vary between individuals in the same environment. The results suggest that smaller persons are prone to be underdressed for moderate activity levels and larger persons are prone to be overdressed. The consequences of these discrepancies place people at different risks for performance loss or cold weather injuries. Nonetheless, even if all are well-dressed at the whole-body level, variation in hand morphology is also expected to influence hand skin temperatures that can be maintained; with smaller hands being more prone to reach skin temperatures associated with dexterity loss or cold weather injuries. In conclusion, this work focusses on bringing cold science to the Arctic warrior, establishing that combating cold stress is not a one size fits all approach.

Spectral analysis of laser speckle contrast imaging and infrared thermography to assess skin microvascular reactive hyperemia.

Post-occlusive reactive hyperemia (PORH) test with signal spectral analysis coupled provides potential indicators for the assessment of microvascular functions. The objective of this study is to investigate the variations of skin blood flow and temperature spectra in the PORH test. Furthermore, to quantify the oscillation amplitude response to occlusion within different frequency ranges. Ten healthy volunteers participated in the PORH test and their hand skin temperature and blood flow images were captured by infrared thermography (IRT) and laser speckle contrast imaging (LSCI) system, respectively. Extracted signals from selected areas were then transformed into the time-frequency space by continuous wavelet transform for cross-correlation analysis and oscillation amplitude response comparisons. The LSCI and IRT signals extracted from fingertips showed stronger hyperemia response and larger oscillation amplitude compared with other areas, and their spectral cross-correlations decreased with frequency. According to statistical analysis, their oscillation amplitudes in the PORH stage were obviously larger than the baseline stage within endothelial, neurogenic, and myogenic frequency ranges (p<0.05), and their quantitative indicators of oscillation amplitude response had high linear correlations within endothelial and neurogenic frequency ranges. Comparisons of IRT and LSCI techniques in recording the reaction to the PORH test were made in both temporal and spectral domains. The larger oscillation amplitudes suggested enhanced endothelial, neurogenic, and myogenic activities in the PORH test. We hope this study is also significant for investigations of response to the PORH test by other non-invasive techniques.

Integrated Thermofluid Lumped Parameter Model for Analyzing Hemodynamics in Human Fatigue State

It is well known that driving while fatigued is dangerous and can lead to serious traffic accidents. However, there is a lack of studies on the mechanism of fatigue. This paper sought to infer changes in the cardiovascular system through hand and head skin temperature peripheral factors via an integrated lumped parameter model. A multi-layer inner structure with variable blood perfusion was used to construct a full-body thermal model. The cardiovascular system model provided blood perfusion using lumped parameters. The peripheral resistance and heart rate in the cardiovascular system model were adjusted to match the experimental temperatures of the head and hands obtained from induced fatigue experiments. The simulation results showed that the heart rate and blood pressure decreased, and the peripheral skin resistance of the hands and head increased after fatigue. A decrease in heart rate and an increase in peripheral resistance affect the magnitude of blood flow to the periphery of the body, leading to a decrease in skin temperature during fatigue. The present integrated model elucidates a key effect of human fatigue on the cardiovascular system, which is expected to help improve the accuracy of fatigue monitoring systems.

Preliminary assessment of the reliability and validity of infrared skin temperature measurements in Rett syndrome.

As clinical trials for Rett syndrome are underway, there is a need to validate potential supplemental outcome measures that reflect important signs and symptoms. Autonomic dysfunction, particularly vasomotor dysfunction, is one potential area for which biomarkers could be developed. In the current study, infrared thermal images of hands and feet from 26 females with Rett syndrome (aged 62months to 39years), and 17 females without known intellectual, genetic or neurological disorders (aged 55months to 39years) were collected. Between-group differences in skin temperature, and temporal stability of skin temperature measures in the Rett syndrome group, and relationships between skin temperature measures and parent-reported and researcher-evaluated indicators of autonomic dysfunction were evaluated. Between-group differences showed lower hand and foot temperatures in the Rett syndrome group. Hand temperature measurements were stable over time and were moderately correlated with parent-reported autonomic symptoms. Foot temperature measurements were more variable than hand temperatures but showed stronger correlations with parent-reported autonomic symptoms. The results provide preliminary support for the reliability and validity of hand and foot skin temperature measures in Rett syndrome. Additional research is needed to replicate these results and evaluate the temporal stability of these measures over shorter time scales.

Effect of moderate-intensity treadmill exercise under different ambient temperatures on peripheral circulatory responses in young healthy adults

Exercise training has the potential for inducing enhancements in peripheral circulation, which can play important preventive and therapeutic roles in peripheral circulatory diseases. However, the relevant published studies show conflicting and inconclusive results. Furthermore, useful or optimum ambient temperature for this purpose has not yet been established. Therefore, we investigated the acute responses in peripheral circulation from exposure of healthy subjects to treadmill exercise under different ambient temperatures; A total of 12 young adult volunteers (males 6, females 6) randomly underwent three sessions of treadmill exercise for 30 min under three different ambient temperatures (10°C, 20°C, and 30°C), at a predetermined exercise intensity. Before and after the intervention, leg skin blood flow (SBF) was measured by laser Speckle flowgraphy and hand skin temperature (ST), by digital thermometry; After the cessation of treadmill exercise, compared to the corresponding baseline values, a significant increase in SBF was observed under all ambient temperature conditions (P&lt;0.005). During intervention, ST showed a significant decrease at 10th min of intervention under all ambient temperatures (P&lt;0.005) with a subsequent increasing trend in it. After intervention, a significant increase in ST was observed under 20°C condition only (P&lt;0.05). Also, after intervention, the observed increase in systolic blood pressure was less significant under 20°C condition; Treadmill exercise appears to be a useful intervention modality in inducing improvements in peripheral circulation. However, exposure to treadmill exercise under or near 20°C ambient temperature might be recommended for the purpose.

Smart detection of indoor occupant thermal state via infrared thermography, computer vision, and machine learning

The ability to measure occupants’ thermal state in real time will enable major advances in the control of air conditioning systems. This study proposes predicting occupant thermal state by a combination of infrared thermography, computer vision, and machine learning. The approach (1) uses cheek, nose, and hand temperatures because they are least subject to blockage by hair, glasses, and clothing; (2) measures the distribution of skin temperatures within geometrically defined sub-areas of the face and hand; and (3) uses temperature differences within and between these areas to eliminate the effects of calibration drift that are unavoidable in thermal infrared (TIR) cameras. Two series of tests were conducted, respectively in an outdoor carport and an indoor environmental chamber, collecting a total of 48,422 sets of cheek, nose, and hand skin temperatures using a TIR camera and computer-vision technology, coupled with 715 subjective responses of thermal sensations. To predict occupant thermal state, Random Forest classification models were built using either absolute skin temperatures (the maximum and median temperatures of cheek and hand segments, and the temperature of the central spot on the nose), or intra- and inter-segment temperature differences of cheeks, hands, and nose. These measurements were found to accurately predict occupant thermal state. Using the maximum and median temperatures for cheek and nose, or for cheek and hand, predicts thermal state with an accuracy of 92–96%. Using only the intra- and inter-segment temperature differences from cheek and nose is 83% accurate; adding the hand temperature differences increases the accuracy to 96%.

Exploring the Impact of Green Walls on Occupant Thermal State in Immersive Virtual Environment

Green walls have been used in built environments as a natural element to bring various benefits, thus improving human health and well-being. However, in conventional virtual environments, the visual connection with a green wall is the only way that this natural element could benefit humans. Unfortunately, the impact of such visual connection on human thermal perception is still not well understood. Thus, we conducted an experimental study with 40 participants comparing the thermal state of two virtual sessions: biophilic (a room with a green wall) and non-biophilic (the same room without a green wall). Both sessions were conducted in a climate chamber under a slightly warm condition (28.89 °C and 50% relative humidity). Participants’ thermal state, skin temperature, and heart rate data were collected. According to the results, participants’ thermal comfort and hand skin temperature were significantly different between the two sessions, and their mean skin temperature was statistically increased over time. The study suggests that before the extent to which the impact of visual stimuli (e.g., green walls) on thermal perception is fully understood, researchers may need to control visual and thermal stimuli separately when using them in immersive virtual environments. Furthermore, the virtual exposure time should be an important consideration when designing experimental procedures.

Safety and health risks for workers exposed to cold thermal environments: A frozen food processing industry perspective.

Environmental temperatures in the fresh food industry vary from 0°C to 10°C, and go below -20°C for the frozen food industry, representing risk for the health and safety of workers involved. The aim of this work was to evaluate the cold thermal stress risks for workers working in a frozen food industry. A total of 27 acclimatized workers (13 male and 14 female) participated in a study which was conducted during 11 working days. The thermal sensation questionnaire and the cold work health questionnaire (CWHQ) were applied to all participants. Additionally, 4 workers were chosen to be fully monitored with a thermometer telemetry capsule for measuring the intra-abdominal temperature and 8 skin temperature sensors. The lowest recorded hand temperature was 14.09°C, lowest forehead 18.55°C, mean skin temperature had variations of 1.10 to 3.20°C along the working period. Highest and most frequent fluctuations were found in the hand and forehead skin temperatures, small changes were found in mean skin temperature. Answers to the CWHQ increase concern on clinical forms of "a frigore", and in two cases the mean body temperature decreased below 35.0°C, which is defined in the current literature as a mild form of hypothermia.

Estimation of core body temperature by near-infrared imaging of vein diameter change in the dorsal hand.

Core body temperature (Tcore ) is a key indicator of personal thermal comfort and serves as a monitor of thermal strain. Multi-parametric sensors are not practical for estimating core temperature because they require long data collection times and a wide variety of settings. This study introduces dorsal hand vein dynamics as a novel indicator along with heart rate (HR) and dorsal hand skin temperature (Thand ) for predicting Tcore during rest following Tcore elevation. Twelve healthy males aged 27 ± 9 years old participated in the experiment. The experimental procedure consisted of a 10-min rest followed by 60 min of passive heat stress induced by leg immersion in hot water at 42°C and a 40-min thermal relaxation period after the legs were removed from the water. A near-infrared (NIR) imaging system was configured to monitor the dorsal hand veins during the entire experimental session. The values of HR, Thand , and Tcore were continuously monitored while the ambient temperature and relative humidity (RH) were maintained in a climate chamber at 20°C and 50%, respectively. Our selected predictor parameters demonstrated similar patterns in the Tcore such that the value increased as a result of passive heat stress and decreased in the thermal relaxation phase. The experimental data were divided into two phases: thermal stress and relaxation. At the resting condition, inclusion of the hand vein diameter (VD) improved the multiple linear regression value (R2 ) about 26%. At the relaxation phase, however, training regressions R2 = 0.68 and R2 = 0.94 were observed in the regression model with and without considering VD, respectively. The test regression value of R2 = 0.88 and the root mean square error (RMSE) of 0.18°C showed good agreement with the predicted values. These findings demonstrate acceptable validity of the non-invasive Tcore estimation at the resting condition. In particular, the inclusion of VD as a predictor in the regression analysis increases the prediction accuracy with a lower RMSE value.

Effect of nursing procedures on the hand skin temperature of female hospital nurses

Nurses' hand temperature may affect patient comfort but has not been investigated. This study aimed to determine female hospital nurses' hand skin temperature and clarify the effects of measurement site, time, nursing procedures, and environment. An observational study. The middle finger, thenar eminence, hypothenar eminence, and medial forearm skin temperature of 29 female hospital nurses was measured at four time points during a day shift and before and after nursing procedures (hand disinfection, hand washing, taking vital signs, hygiene care, and positioning). Mean hand skin temperature was in the range of 29-32°C with interpersonal variations. Mean skin temperature at the medial forearm was 31.94-32.35°C (SD 0.87-1.52°C) and at the middle finger, 29.73-31.07°C (SD > 3°C). Time-dependent skin temperature fluctuations were confirmed on the middle finger (p = .022), and thenar (p = .005) and hypothenar eminence (p = .001). There were weak correlations between skin temperature and environmental factors, including ambient temperature (ρ = .194-.266), humidity (ρ = -.309 to -.319), and hospital room wind speed (ρ = .253-.314). The skin temperature dropped significantly after hand disinfection and handwashing at all measurement sites (middle finger: -1.30 and -3.56°C, respectively; thenar eminence: -1.19 and -3.32°C; hypothenar eminence: -0.80 and -3.39°C; medial forearm: -0.21 and -1.60°C). These findings may raise nurses' awareness of their skin temperature. Moreover, our study highlights the need to develop countermeasures to ensure optimal nurses' skin temperature and patient comfort.

ВАЗОМОТОРНЫЕ РЕАКЦИИ НА ЛОКАЛЬНОЕ ОХЛАЖДЕНИЕ У МОЛОДЫХ ЛИЦ С НИКОТИНОВОЙ ЗАВИСИМОСТЬЮ

Tobacco smoking, as a harmful individual habit, aggravates the negative environmental effects on health in people living in the northern regions of Russia, by increasing the incidence of diseases of the cardiovascular and respiratory systems, and oncological diseases. This study was aimed at elucidating the vasomotor reactions on local cooling in young people with nicotine addiction. Materials and methods. Twenty four practically healthy people (13 m, 11 f) aged 18-27 years were enrolled to the study. Of these, 16 subjects with initial stage of nicotine addiction formed the study group, and 8 non-smoking subjects served as a reference group. The degree of nicotine addiction was assessed with the Fagerstrom test and the smoking index. The local cold test (LCT) was used to study vasomotor reactions. The autonomous regulation was estimated by analyzing the time- and frequency-domain characteristics of heart rate variability (HRV). Results. In the group with nicotine addiction, increased cold-induced vasoconstriction was revealed from the dynamics of the hand skin temperature during LCT. Also, this group mwas characterized by decreased vagotonia seen as lower values of time- (SDNN, RMSSD, pNN50 and CV) and frequency- domain (TP, HF and LF) parameters of HRV. The functional test with deep controlled breathing revealed in this group lower reactivity of neurogenic mechanisms of heart rate control. Among subjects with higher number of cigarette consumption, HRV changes which corresponded with adaptation disorders were more notable. Conclusion. Individuals with initial degree of nicotine addiction were characterized by the impaired reactivity of the central and peripheral parts of the circulatory system what means lower health capacity of the organism. Increased vascular reactivity during LCT, as well as the impaired adaptation seen with HRV analysis, could serve as early indicators of the systemic effects of tobacco smoking.

Out-of-body experience favors emotional memory consolidation

Body ownership reflects our ability to recognise our body at a certain location, enabling us to interact with the world. Emotion has a strong impact on memory and body ownership; interestingly, skin temperature may at least in part mediate this impact. Previous studies have found that out-of-body experiences (OBE) impair memory encoding and cause skin temperature to drop. In the present study a new method for inducing OBE was designed and their impact on a different stage and type of memory processing (emotional memory consolidation) and on skin temperature was investigated. In our experiment, we presented three types of emotional pictures (neutral, pleasant, unpleasant) before inducing OBE and testing our participants’ recognition memory in a retrieval session. Throughout the whole experiment, both neck and hand skin temperature were measured using iButtons. Participants’ performance was calculated using d-prime and statistical analyses included one-way ANOVA, probing the relationship between the score on the OBE questionnaire, performance and skin temperature; we also compared the differences between the experimental and a control group. Results showed that OBE favour emotional memory consolidation and cause a temperature increase, supporting the embodied cognition theory as proposed by Anderson (2003). Future studies should expand our findings, to rule out that participants experiencing OBE could have a better memory at baseline or that temperature could be increased due to other reasons.

Bilateral skin temperature drop and warm sensibility decrease following modulation of body part ownership through mirror-box illusion

The implicit and explicit awareness of owning a body and its parts is a constant accompaniment in our everyday life and our interaction with the outside world. The way in which we build and maintain a coherent sense of body ownership is not fully understood. It has been postulated that the integration between exteroceptive, interoceptive, and proprioceptive signals may play a fundamental role in the sense of body ownership. For instance, studies on healthy subjects and brain-damaged patients have suggested that alterations in the sense of body ownership are coupled with autonomic signal changes, such as thermoregulatory reactions. However, the available evidence is conflicting, possibly due to shortcomings in the experimental paradigm that previous studies have adopted. In this study, we explore the relationship between body ownership, thermoregulation, and thermal sensitivity through a novel application of the mirror-box illusion paradigm, overcoming some of the limitations of previous studies. We find a bilateral decrease in hand skin temperature, together with reduced thermal sensitivity for warm thermal stimuli following the induction of the illusion of ownership towards the participant's reflected hand. These findings demonstrate the importance of the orchestration of exteroceptive (e.g., visual), autonomic (e.g., body temperature) and proprioceptive (e.g., position and movement of the body) signals in maintaining a coherent sense of body ownership.

Thermal Sensation in Older People with and without Dementia Living in Residential Care: New Assessment Approaches to Thermal Comfort Using Infrared Thermography.

The temperature of the indoor environment is important for health and wellbeing, especially at the extremes of age. The study aim was to understand the relationship between self-reported thermal sensation and extremity skin temperature in care home residents with and without dementia. The Abbreviated Mental Test (AMT) was used to discriminate residents to two categories, those with, and those without, dementia. After residents settled and further explanation of the study given (approximately 15 min), measurements included: tympanic membrane temperature, thermal sensation rating and infrared thermal mapping of non-dominant hand and forearm. Sixty-nine afebrile adults (60–101 years of age) were studied in groups of two to five, in mean ambient temperatures of 21.4–26.6 °C (median 23.6 °C). Significant differences were observed between groups; thermal sensation rating (p = 0.02), tympanic temperature (p = 0.01), fingertip skin temperature (p = 0.01) and temperature gradients; fingertip-wrist p = 0.001 and fingertip-distal forearm, p = 0.001. Residents with dementia were in significantly lower air temperatures (p = 0.001). Although equal numbers of residents per group rated the environment as ‘neutral’ (comfortable), resident ratings for ‘cool/cold’ were more frequent amongst those with dementia compared with no dementia. In parallel, extremity (hand) thermograms revealed visual temperature demarcation, variously across fingertip, wrist, and forearm commensurate with peripheral vasoconstriction. Infrared thermography provided a quantitative and qualitative method to measure and observe hand skin temperature across multiple regions of interest alongside thermal sensation self-report. As an imaging modality, infrared thermography has potential as an additional assessment technology with clinical utility to identify vulnerable residents who may be unable to communicate verbally, or reliably, their satisfaction with indoor environmental conditions.

Machine learning algorithms applied to a prediction of personal overall thermal comfort using skin temperatures and occupants' heating behavior

Thermal comfort modeling has been of interest in built environment research for decades. Mostly the modeling approaches focused on an average response of a large group of building occupants. Recently, the focus has been shifted towards personal comfort models that predict individuals' thermal comfort responses. Currently, thermal comfort responses are collected from the occupants via survey. This study explored if the thermal comfort of individuals could be predicted using machine learning algorithms while relaying on the set of collected inputs from an experiment. The model was developed using experimental data including collected from a previously performed experiment in the climate chamber. Two different approaches based on the output data (thermal sensation and thermal comfort votes) and five different sets of input variables were explored. The algorithms tested were Support Vector Machine with four different Kernel functions (Linear, Quadratic, Cubic and Gaussian) and Ensemble Algorithms (Boosted trees, Bagged trees and RUSBoosted trees). The combination of occupants' heating behavior with a personal comfort system (PCS), skin temperatures, time and environmental data were used for the development of personal comfort models to predict individuals' thermal preference. The study investigated the novel combination of inputs such as the use of skin temperature and settings of the personalized heating system as parameters in predicting personal thermal comfort. The results showed that personal comfort models among all tested approaches and subjects showed the best median accuracy of 0.84 using RUSBoosted trees. Individually looking, the approach using thermal sensation output produced better prediction accuracy. On the other hand, the models based on inputs that consisted of PCS control behavior and mean and hand skin temperatures produced the best prediction accuracy when assessing all tested algorithms. The main limitation of the study is the number of test subjects, and further recommendation is to perform more experiments.