Ventilation and supply air distribution play an important role in reducing exposure to airborne pathogens in hospital isolation rooms. Effective supply air distribution should dilute high concentrations readily close to the source and direct them away from the breathing zone of the occupants. In this study a healthcare worker (HCW) exposure to patient exhaled airborne contaminants was assessed with a typical total volume mixing ventilation (MV) and with a local downward ventilation (LDV) above the patient bed. The experiments were carried out in a full-scale isolation room mock-up with breathing thermal manikins simulating the HCW and the patient. Smoke visualisations and air speed measurements show that LDV increases air movement and enables more effective flushing of the patient's upper body compared to MV. Tracer gas measurements show that several factors, like HCW location, air exchange rate, and occupant movement, affect the HCW exposure and that LDV can reduce the exposure notably compared to MV, at least near the patient. Additionally, thermal comfort measurements indicate that LDV can produce adequate thermal conditions for the patient. These findings can be utilised when designing better ventilation solutions for hospital isolation and patient room environments.

Exposure to high temperatures in industrial environments can lead to heat stress and a decline in physiological performance. The use of evaporative cooling garments has been proposed as an effective strategy to reduce body temperature and enhance potential thermal comfort. This study` aimed to compare the cooling capacity of two types of evaporative cooling vests, including a fan-assisted vest and a microtube‑based evaporative cooling vest (compressed‑air supplied), under controlled hot-dry conditions. In this study, the two types of cooling vests were evaluated in a climatic chamber at an ambient temperature of 35°C and relative humidity levels of 20% and 40%. The cooling capacity of the cooling vests was assessed by measuring the cooling power using a thermal manikin and calculating the rate of water evaporation. Data are presented as mean ± standard deviation, and differences between conditions were analyzed using a paired t-test. The mean cooling capacity of the fan-assisted cooling vest at 20% relative humidity was 83 ± 8W, compared to 56 ± 5W for the microtube‑based evaporative cooling vest (p < 0.01). At 40% relative humidity, the cooling capacity of the fan-assisted cooling vest was 74 ± 4W, while that of the microtube‑based evaporative cooling vest was 47 ± 4W (p < 0.05). Additionally, both the evaporation rate and evaporative efficiency of the fan-assisted cooling vest were significantly higher than those of the microtube‑based evaporative cooling vest (p < 0.01). The results indicate that, on the thermal manikin, the fan‑assisted vest provides superior performance in reducing heat load, whereas the microtube‑based cooling vest offers more stable but less effective cooling. These objective findings suggest that, under hot and dry conditions, the fan-assisted design may be more suitable for applications requiring high cooling capacity, while the microtube‑based cooling vest may be considered for prolonged heat exposure in settings with access to compressed air. However, the actual thermal comfort benefits for human users should be verified in future human‑subject studies.

CFD-driven design of a thermal foot manikin: Enhancing temperature uniformity and environmental adaptability for outdoor footwear comfort studies

Multi-dimensional assessment of metal welding fumes exposure and oxidative stress-driven health risks: Insights from external monitoring, respiratory replica monitoring, and DTT activity.

Climate change has exacerbated heat stress, particularly for outdoor workers. Evaporative cooling vests (ECVs) mitigate occupational heat stress. Their cooling capacity depends on the structural design, air temperature, air velocity, and humidity. This study investigated the cooling capacity and efficiency of four ECV designs under various environmental conditions. Four ECVs—polymer-based punched (ECVPP), polymer-based (ECVPB), cellulose-based (ECVCB), and TECHNICHE (ECVTECH)—were evaluated via a thermal manikin under controlled conditions (ambient temperatures: 35 °C and 40 °C; relative humidity: 20% and 40%; air velocities: 0.1, 0.4, and 1.0 m/s, respectively). The cooling capacity was measured by monitoring the energy consumption of the manikin over two-hour periods. The efficiency was calculated as the cooling capacity relative to the latent heat of water evaporation. Thermal imaging captured the surface temperature distribution. At 40 °C, ECVCB and 30 °C, the ECVPP consistently outperformed the other vests, achieving cooling capacities of 81.7 W and 78.5 W, respectively. These peak values were observed under higher air velocity conditions (1 m/s). Correlations (R = 0.9, p < 0.001) between the amount of evaporated water and the cooling capacity were observed. Thermal imaging confirmed that the progressive cooling capacity decreased due to evaporation—efficiency varied by vest design, highlighting the superiority of ECV_CB. This study highlights the performance of cellulose-based ECVs in hot, dry conditions, driven by enhanced evaporation rates. Higher air velocities improved the cooling capacity but reduced the efficiency, underscoring the need to balance airflow, humidity, and vest design for optimal performance. These findings provide insights for improving ECV functionality in occupational heat stress scenarios.

Deployed armed forces and the public engaged in outdoor activities are at high risk for mosquito bites and the diseases they transmit. Current mosquito bite-resistant garments prevent blood-feeding with slow-release insecticide formulations. Many people today want to avoid contact with pesticides, especially in their clothing. Insecticide treated clothing also is costly and requires regulatory agency approvals. Using mosquito bite-resistant mathematical textile models and a WholeGarment® knitting technique, a seamless garment was constructed with military-compliant, no-melt, no-drip flame retardant yarns using an AiryPique knit architecture. The garment was 99.5% bite proof in walk-in cage bioassays with 200 Aedes aegypti host-seeking mosquitoes where the human subjects did not move for 20 min. A standard flame test and a PyroManTM flammability study validated the garment’s fire protection, a requirement for military uniforms. The thermal physiological comfort tests (air permeability, wetting time/radius, thermal resistance, evaporative resistance, and sweating thermal manikin test) were similar to current army combat uniforms and appropriate for use in everyday clothing. Bite prevention occurred by physically blocking the insect mouth parts from obtaining a blood meal. The knitting technique is well-suited for mass production of bite-resistant clothing through automation, significantly reducing labor, time, and cost by optimizing “fit on demand” for different body types compared to traditional manufacturing methods. This innovation provides a non-insecticidal, safe, scalable, and efficient solution for protecting individuals against mosquito bites.

There is no consensus regarding the optimal design parameters of PCM cooling garments for reducing heat strain under low-level radiant heat exposure, nor on their differentiated configuration strategies for different body regions. This highlights the urgent need for a systematic investigation of the factors affecting clothing performance. In this study, the effects of radiant intensity, PCM packet gap, and phase change temperature on the heat transmission and thermal protection performance of different torso regions under uniform thermal radiant intensity were explored. The investigation was conducted using the thermal manikin ANDI, employing an experimental strategy that combined single-factor analysis with orthogonal optimization. The results indicate that the effects of these three factors on the performance of each vest region are relatively independent of one another. Among these factors, radiant intensity has the most significant impact. Based on the human body’s physiological characteristics, it is preferable to use a smaller PCM packet gap in the chest and lower back compared to other regions, and a higher phase change temperature in the chest to prolong cooling time. The acceptable wearability of the PCM cooling vest was further confirmed by wearing trials. These findings can provide methodological support for establishing performance evaluation standards for PCM cooling garments and the development of high-performance personal thermal protection equipment.

Cranial remodeling orthoses (CRO) are essential in the treatment of positional cranial deformities of newborns. Traditional CROs, made from thermoplastic materials, often have limited ventilation, affecting thermal comfort and patient compliance. Recent advances in 3D printing offer new possibilities for optimizing airflow and material properties. However, a lack of comparative studies on the thermal behavior of 3D printed versus thermoplastic CROs remains a significant research gap. This study experimentally evaluated the thermal performance of two types of CRO: a conventional thermoplastic model and a 3D printed design. Infrared thermography was used to measure temperature changes in three identical pediatric head models under controlled conditions. A novel computational framework ensured consistent measurement across different orthotic designs. For both orthoses, thermal and evaporative resistance was measured using a thermal manikin according to ISO 15831. The thermoplastic CRO showed a drop in temperature from 3.6 to 5.0 ° C per hour. In contrast, the 3D printed CRO showed a faster cooling rate of 3.9–5.6 °C per hour. The tests performed on the thermal manikin confirmed a 20% reduction in the resistance to water vapor and a more gradual development of thermal resistance in the 3D printed CRO. These findings highlight the need for standardized CRO-specific thermal assessment protocols. This study provides the first direct comparison of thermal performance in 3D-printed and thermoplastic CROs. The results support a shift toward thermally optimized, patient-centered CRO solutions. • First experimental comparison of thermal behavior in 3D printed versus thermoplastic cranial remodeling orthoses. • Innovative framework for automatic temperature mapping, ensuring spatially accurate thermal comparisons across different orthotic designs. • Direct implications for clinical practice, allowing evidence-based material selection to improve patient compliance and treatment outcomes.

Medical personnel wearing barrier clothing protecting against infectious agents are at risk of heat stress resulting from limited heat exchange with the environment. The aim of the study was to assess the impact of changing underwear on the thermal parameters of protective clothing sets and on the expected safe working time. The study used a Newton thermal manikin to determine the thermal insulation and water vapor resistance of clothing sets consisting of three types of underwear (standard medical underwear and short and long thermal underwear) worn under two types of barrier suits. The obtained data were used to conduct physiological simulations in the Predicted Heat Strain (PHS) program, estimating the time it takes for core body temperature to rise to 38 °C in conditions of 22 °C and 35 °C. The results showed that replacing medical underwear with thermal underwear at 22 °C extended safe working time by 24%. In hot conditions (35 °C), the positive impact was smaller, extending working time by a maximum of 4%. Changing the inner layer is an effective method of improving comfort and safety in barrier clothing, especially in thermoneutral conditions.

With the rapid development of the automobile industry, the public’s demand for automobile diversification is growing steadily.People are no longer satisfied with basic driving convenience, more attention is now directed to the thermal comfort of the cabin. In order to build the relationship between in-vehicle environment parameters and thermal comfort index, the concept of equivalent temperature (Teq) was introduced, and then the DTM reflecting the thermal comfort of the human body was applied to the simulation of ANSYS Fluent. For a specific working condition of the vehicle air conditioning, the equivalent temperature of the in-vehicle environment was tested by the DTM, and it was found that the highest Teq (approximately 27°C) was observed in the foot region of the passenger. The Teq of most areas of the passenger’s body was relatively low, especially in the temperature sensitive torso, it was about 15–20°C. Numerical calculations for the same working conditions were carried out using the DTM. By comparing the results of Teq between the DTM and the physical thermal manikin, it was found that the results are very similar, the Teq deviation was less than 3℃, indicating that DTM can be used to measure Teq instead of physical thermal manikin. Finally, the DTM model was used to optimize the air outlet of the vehicle air conditioning system. The results showed that the best comfort was achieved when the air velocity was 4 m/s, the outlet temperature was 25℃, and the airflow was directed toward the occupant’s abdomen.This study demonstrates that DTM can replace physical experiments in thermal comfort evaluation, providing an efficient and low-cost approach for optimizing vehicle HVAC design.

This paper presents an innovative digital twin solution for thermal manikins used to evaluate indoor environmental quality in buildings. While digital twin technology is gaining traction across industrial sectors, its adoption in building sector remains limited due to the industry's slow integration of innovative technologies. The research addresses the need for more accessible tools to analyze thermal comfort, which is often treated superficially in building design phases despite its fundamental importance for occupant well-being and energy efficiency. Traditional approaches rely on costly physical testing or simplified models that fail to capture complex human-building thermal interactions, leading to suboptimal designs and post-occupancy comfort issues. The proposed solution consists of a MATLAB application that provides an intuitive interface for monitoring thermal comfort parameters and real-time visualization of thermophysiological models applied to thermal manikins. A key innovation is the bidirectional data integration with ANSYS Fluent solver, enabling real-time simulations using data extracted from physical thermal manikin and vice versa. This work contributes to understanding and implementing digital twin concepts in thermal comfort evaluation, offering an innovative technological platform that balances occupant comfort with energy efficiency while providing a foundation for future research in this evolving field.

The paper describes methods for measuring the thermal resistance of protective clothing intended for use in extreme Arctic conditions. It discusses conventional approaches, such as calorimetry and thermal manikins testing, and contemporary techniques, including infrared thermography, computer modeling, and smart textile sensors. Key issues related to the discrepancy between laboratory data and real-life operating conditions are identified, including the influence of wind load, high humidity, and temperatures below −50 °C. The paper analyzes the limitations of applicable standards (GOST 12.4.303-2016, ISO 15831:2004) proposes ways to improve them, including the introduction of correction factors to consider hybrid climatic factors. The paper focuses on promising areas, such as the integration of artificial intelligence for data analysis, the development of nanostructured insulation, and the harmonization of Russian standards with international requirements. It highlights the need for an interdisciplinary approach combining materials science, climate science, and digital technologies to improve the safety and performance of protective clothing in the context of increasing human impact on Arctic regions.

The escalating climate change and extreme weather conditions have highlighted the limitations of conventional textiles in body temperature regulation Phase-change thermoregulatory fibers can maintain constant temperature when environmental conditions fluctuate, effectively meeting human comfort requirements. To investigate the temperature-regulating properties of TempSolution viscose/cotton thermoregulatory yarn in seamless knitted fabrics, this study examined three different knitted fabric structures along with varying blend ratios and linear densities of TempSolution viscose/cotton yarn as experimental variables. According to a full factorial experimental design, eighteen fabric samples and corresponding garment prototypes were produced on a seamless circular knitting machine. Differential scanning calorimetry (DSC) and thermal manikin tests were conducted to compare the thermoregulatory performance and thermal comfort of seamless knits with different yarn compositions and structures. The results demonstrated that among the fabric structures, the 1 + 3 mock rib configuration exhibited superior thermal resistance and comfort properties. Regarding yarn types, the 50/50 TempSolution blend with 50 s yarn count showed relatively superior performance across all test parameters, providing a theoretical foundation for developing phase-change knitted fabric.

Heated clothing is an alternative to passive thermally insulating clothing used so far, made of thick, multi-layered fabric compounds. In this work, a personalized two-layer heated clothing ensemble for mountain rescuers was developed. It consisted of an electrically heated inner suit and an outer suit made of waterproof laminate. Total thermal insulation and local thermal insulations were determined using a thermal manikin. The heating system's performance was assessed by comparing these results with those obtained with the heating turned off in the same ensemble, as well as with a down jacket added. It was confirmed that a thick thermally insulating layer (down jacket) can be eliminated through the application of electric heating. Heating improved the resultant effective thermal insulation of the clothing ensemble by 52% at a total power of 28.4 W. This exceeded the value obtained with the additional down jacket and no heating by 4%.

Purpose The purpose of this paper is to construct a human body-garment-environment integrated model in CFD simulation to evaluate the heat flow change in an outdoor service shirt. The proposed model as well as the method can be used to analyze the undergarment microenvironment and to predict the thermal comfort of the garment. Design/methodology/approach In this paper, the clothing fabric in the climate chamber was considered as a classical porous medium model, and the heat transfer mechanism in the microenvironment of a thermal manikin wearing a single-layer long-sleeved outdoor service shirt was investigated by using the thermostatic method under different levels of wind environments. The human body model consistent with the thermal manikin and the relevant clothing model of a shirt with the real size is established by using CLO3D software. Heat transfer and fluid change in a single-layer shirt subjected to the wind were simulated in an FEM software. The mathematical model of heat transfer and fluid changes in a single-layer shirt subjected to wind was established. Findings By using the physical property parameters of the real fabric materials, experiments were conducted with different wind speeds, combined with the simulation function of the climate chamber using the thermostatic method. Finally, numerical simulation results were analyzed and compared to the results of a real thermal manikin to validate the feasibility of the simulation of the characteristics of the change of heat flow under the clothing of the single-layer outdoor service shirts in FLUENT. The relative error between the simulation results and the actual results of the space temperature in each region under the garment using this numerical simulation technique was explored, with an error range of <6.67%, verifying the feasibility of the simulation model. Originality/value A human body-garment-environment integrated model in CFD simulation was established to evaluate the heat flow change in a typical shirt. The detailed parameters of the shirt fabric were determined by testing all aspects of the garment fabric. The actual porosity of the sample outdoor service shirt was determined by mercuric pressure, and the parameters obtained were used to create a closer simulation of the material data. A real-size human body model and the relevant garment model were created in the simulation process. The method provided a feasible numerical way to evaluate and predict heat transfer and the microenvironment of the garment and to produce robust and reliable simulation performance.

Study of geometric and thermal boundary conditions settings for thermal manikin simulation in cabin

Unraveling the applicability and thermal performance of PCM-impregnated wood in personalized comfort systems: Thermal manikin verification

Purpose In cold weather conditions, the thermal performance of multi-layered fabrics plays a critical role in maintaining comfort and safety. This study introduces a unique testing apparatus that has been designed and developed to evaluate the thermal characteristics of multi-layer fabrics specifically designed for extreme cold weather conditions. Design/methodology/approach The thermal conductivity measurement instrument employs a dual-plate methodology, incorporating precise procedures to replicate extreme cold conditions (down to −45°C) in the top zone using dry ice, while also establishing a regulated hot zone (bottom zone) that mimics human skin temperature (33°C) through the use of an electric heater and a proportional-integral-derivative (PID) temperature controller. Findings The experimental apparatus revealed consistent temperature fluctuations (±<0.5°C) and good thermal stability in the bottom zone during both short and long-duration testing periods. In the cold zone, the instrument effectively maintained lower temperature fluctuations (±<2°C) during shorter testing periods. However, because of rapid dry ice sublimation, extended testing durations showed larger temperature fluctuations (±˜5°C). Research limitations/implications These findings also demonstrate the limitations of dry ice as a cooling medium for extended periods of testing time. Practical implications This study aims to enhance the functioning of multi-layer fabrics, which are in demand for cold-weather clothing, based on the tested equipment. Originality/value Though several commercial testing devices and research models based on steady-state and non-steady-state (transient) approaches have been developed, there is still a significant gap in accurately simulating cold weather conditions when evaluating cold weather clothing, with the exception of the thermal manikin method.

Thermal resistance, evaporative and convective performance of protective clothing under coupled hypobaric and thermal stress: a thermal manikin experimental study

Postmastectomy bras are essential for providing support and comfort to breast cancer survivors during recovery. However, existing designs primarily focus on functionality while often overlooking physiological comfort, which affects prolonged wearability. This study provides a comparative evaluation of mastectomy bras with different prosthetic materials, offering insights into their thermal and evaporative resistance measured using a thermal manikin under both dry and wet conditions. Results indicate that bras with silicone prostheses exhibit lower thermal resistance ( R cf = 0.051 ± 0.002 K m 2 /W) and evaporative resistance ( R ef = 12.1 Pa m 2 /W) compared to foam prostheses, facilitating greater heat dissipation and moisture permeability. This research highlights the influence of prosthetic design, particularly the wavy back structure of silicone prostheses, in enhancing airflow and reducing heat buildup. In addition, the nonabsorbent nature of silicone contributes to moisture runoff, affecting weight retention in the bra. This study provides clinically relevant insights into how prosthetic material and design influence thermal regulation and overall physiological comfort, which can inform future advancements in mastectomy bra development. By addressing both material selection and structural design, these findings contribute to optimizing postmastectomy garments for improved patient comfort. Future research should incorporate wear trials to validate these results and refine prosthetic bra designs for broader clinical applications and user-centered improvements.