Firefighter Protective Clothing Research Articles

Implementation of Numerical Model for Prediction of Temperature Distribution for Metallic-Coated Firefighter Protective Clothing

The aim of this study is to predict the distribution of temperature at various positions on silver-coated firefighter protective clothing when subjected to external radiant heat flux. This will be helpful in the determination of thermal protective performance. Firefighter clothing consists of three layers, i.e., the outer shell, moisture barrier and thermal liner. The outer shell is the exposed surface, which was coated with silver particles through a physical vapor deposition process called magnetron sputtering. Afterwards, these uncoated and silver-coated samples were exposed to radiant heat transmission equipment at 10 kW/m2 as per the ISO 6942 standard. Silver-coated samples displayed better thermal protective performance as the rate of temperature rise in silver-coated samples slowed. Later, a numerical approach was employed, contemplating the impact of metallic coating on the exterior shell. The finite difference method was utilized for solving partial differential equations and the implicit method was employed to discretize the partial differential equations. The numerical model displayed a good prediction of the distribution of temperature at different nodes with respect to time. The comparison of time vs. temperature graphs at different nodes for uncoated and silver-coated samples acquired from numerical solutions showed similar patterns, as witnessed in the experimental results.

The heat and moisture transfer model of firefighter protective clothing

This paper presents a model of heat and moisture transfer through multilayer firefighter protective clothing, which for the first time has taken into account all the major heat and moisture transport mechanisms including conductive and convective heat transfer, two-flux radiative heat transfer, moisture bulk flow, moisture absorption/desorption by fibers, moisture diffusion and phase change. The model was solved by Crank–Nicolson scheme of the finite difference method. Numerical analysis showed that our model can accurately predict the second-degree burn time with an error ranging from 0.37% to 3.55% for different types of clothing assemblies. With this model, the distributions of heat and moisture within the protective clothing system are elucidated and the relative importance of key clothing parameters on thermal protection better understood. It revealed that the thickness of the moisture barrier layer has the greatest influence on the skin burn time. This study is significant in providing a theoretical framework for optimizing the design of thermal protective clothing.

Enhancing heat protection performance of firefighters’ protective clothing: A comparative analysis of fabric and knit structure in the lining of multi-layered construction

A firefighting protective clothing item is an important piece of equipment that can protect firefighters from the risk of burns during firefighting and rescue activities. In this study, a method to improve the heat protection performance of firefighter protective clothing lining was proposed, while consulting with textile experts. The protective performance effects of flame and radiant heat were investigated according to the quilting spacing (25.4, 50.8, and 76.2 mm) of the lining and weaving method (fabric or knitted) used for the multi-layered structure of the protective clothing. The experiments conducted to evaluate the impact of different weaving methods on the protective performance of firefighter clothing against flame, radiant heat, and combined flame/radiant heat revealed that the knitted lining exhibited excellent protection performance. Specifically, the knitted lining demonstrated a delayed effect in temperature increase, with maximum delays ranging from approximately 2.2–4.0 s for flame protection experiments, and 5.7–7.4 s for radiant heat protection experiments. For knitted lining, one thread is woven in an interlocking manner; thus, the heat resistance is higher and thermal conductivity is lower owing to the formation of a space compared that for a fabric lining. The results suggest that the weaving method affects the heat transfer according to the formation of space and change in the thickness of the clothing. The findings of this study could be useful for many purposes, such as cost effective and quick analysis of the expected performance of a design or weaving method.

Impact of conventional and advanced cleaning techniques on the durability of firefighter turnout ensembles

The concern for firefighters’ occupational exposure to harmful contaminants is growing due to the increase in health issues in the firefighting community. At such times, effective decontamination of personnel and equipment is an essential component of a hazard mitigation strategy. The current decontamination practices used for firefighter protective clothing have been shown to not be very effective. Hence, the scientific community is looking for several alternatives to conventional washing procedures. Liquid carbon dioxide (CO2) has been used in laundering and has distinct advantages over conventional dry-cleaning solvents such as perchloroethylene. The following study is aimed to assess how different washing procedures affect the durability of the turnout material. The study includes using three washing procedures on different samples: 1) conventional washing procedure, 2) liquid CO2 washing procedure, and 3) a high-temperature washing procedure. Samples for durability testing were constructed from a common aramid fabric used in firefighter turnout ensembles. These swatches were subjected to different washing techniques. The durability assessment was performed for physical testing of the samples, visual inspection, water repellency, and quantifying color changes using spectrophotometric analysis. The conventional wash and high-temperature washing affected the durability of the outer shell material in a significant manner. The liquid CO2 process did not affect the samples’ water repellency or physical strength. In contrast, conventional and high-temperature washing significantly affected the durability of the outer shell material. However, all samples met the criteria for tearing strength outlined in the NFPA 1971 standard subsection 7.1.11.

An Extended Model for Analyzing the Heat Transfer in the Skin-Microenvironment-Fabric System during Firefighting.

This study proposed an extended multi-layer heat transfer model to simulate skin burns of firefighters during firefighting. The proposed model takes into account the effect of fabric movement frequencies, fabric movement amplitudes and human body movement speeds on the heat transfer between the skin and the heat source under low-level radiative exposure. The simulation performance was validated against the simulations in the published literature in terms of the heat transfer in the multi-layer fabric system, skin temperature and skin burns. The results indicated that the fabric periodic movement caused by human body movement decreased the time to skin burns and the skin temperature increased with increasing fabric movement amplitude. During firefighting, the time to 2nd degree burn was 33.3-35.2% shorter at medium human body movement speed than at low and high movement speeds. Furthermore, at low movement speeds, the time to 2nd degree burn was negatively associated with fabric movement amplitude, whereas it was delayed by 12.9-29.8% at the fabric movement amplitude of 2.5 mm at medium and high human body movement speeds. This research provides foundational knowledge for the development of a new generation of firefighters' protective clothing (FPC) and the assessment of skin burns in firefighters.

A Database of Static Thermal Insulation and Evaporative Resistance Values of Dutch Firefighter Clothing Items and Ensembles.

The rescue operations' environment can impair firefighters' performance and increase the risk of injuries, e.g., burns and hyperthermia. The bulk and carried weight of heavy protection contributes to lower physical performance, higher metabolic load and internal body heat production. For recommending optimal protection for the tasks and incident scenarios, knowledge of clothing thermal properties is needed. However, detailed data on firefighter protective clothing systems are not available. The aim of the study was to provide scientific background and a dataset that would allow for validation of thermo-physiological models for task-specific conditions of rescue work. Thermal insulation of 37 single items and their variations and 25 realistic protective clothing ensembles were measured on a thermal manikin. Twelve (12) ensembles that evenly covered the whole insulation range were selected for evaporative resistance testing. The equations for summing up individual item's insulation to ensemble insulation and calculating clothing area factor were derived from the dataset. The database of a firefighter clothing system was created. In addition, the local and regional thermal properties of the clothing ensembles were provided for use in future validation of advanced thermo-physiological models for rescue worker exposure predictions and for designing decision aid tools.

Effect of cooling on static postural balance while wearing firefighter’s protective clothing in a hot environment

Objectives. Postural imbalance can result from hyperthermia-mediated muscular fatigue and is a major factor contributing to injuries from falling. The objective of this study was to investigate the effect of exercise-induced hyperthermia and the impact of cooling on postural balance while wearing firefighters’ protective clothing (FPC) in a hot environment. Methods. A portable force platform measured postural balance characterized by postural sway patterns using center of pressure metrics. Twelve healthy, physically fit males were recruited to stand on the force platform once with eyes open and once with eyes closed before and after treadmill exercise (40% V ˙ O 2 max ) inside an environmental chamber under hot and humid conditions (30 °C and 70% relative humidity) while wearing FPC. Subjects participated in two randomly assigned experimental phases: control and cooling intervention. Results. A significant increase in physiological responses and postural balance metrics was observed after exercising in the heat chamber while wearing FPC. Cooling resulted in a significant effect only on postural sway speed after exercise-induced hyperthermia. Conclusions. Hyperthermia can negatively alter postural balance metrics, which may lead to an increased likelihood of falling. The utilization of body cooling reduced the thermal strain but had limited impact on postural balance stability.

Effects of personal protective clothing on firefighters’ gait analyzed using a three-dimensional motion capture system

Objectives. The effects of personal protective clothing (PPC) on firefighters’ gait were investigated to develop high-performance PPC. Methods. Thirteen participants participated in human trials with three types of PPC (firefighter protective clothing [FPC], semi-enclosed chemical protective clothing [CPC_semi] and fully enclosed chemical protective clothing [CPC_full]) and a T-shirt (control clothing [CON]). A three-dimensional (3D) motion capture system was used to obtain gait parameters (step length, step width, stride frequency, gait speed and toe-out angle) and the range of motion (ROM) of the joints (hip, knee and ankle). Results. PPC produced an increase in step width (23.4%, p > 0.05), but the gait speed (9.1%) and stride frequency (6.4%) decreased compared with the CON results. ROM is affected by the PPC type and joint. FPC and CPC_semi had no significant effect in terms of ROM of the hip and knee besides the landing angle of the knee. However, CPC_full had a significant effect on the maximum extension angle of the hip and maximum flexion angle of the knee, which reached up to 27.2%. Conclusion. The ROM of the firefighter’s lower limbs was limited by PPC. This study offers insights into next-generation PPC design and development, as well as guidelines for training and firefighting.

Firefighting: Challenges of Smart PPE

The continuous research and development regarding firefighters’ personal protective equipment (PPE) has led to significant improvements in recent decades. Despite the evolution of firefighters’ PPE, every year an undesirable number of firefighters are seriously burned during firefighting operations, with some of them eventually losing their lives. The protection given by firefighters’ PPE can be further increased with the incorporation of smart textiles in the personal protective equipment, namely, wearable electronics (i.e., integrated sensors to monitor diverse parameters: heart rate, oxygen saturation, carbon dioxide detector, and setting real-time communication with a command post) and advanced materials such as phase change materials (PCMs). The evolution of firefighters’ PPE has been followed by an evolution and update in the international and national standards that specify performance requirements for firefighters’ protective clothing for structural and wildland firefighting as well as technical rescue. This study will focus on the analysis of firefighters protective clothing evolution regarding the use and integration of advanced smart materials, namely, phase change materials, taking into consideration the evolution and requirements of international and European standards as well as national legislation for firefighters’ protective clothing.

Impact of repeated radiative heat exposure on protective performance of firefighter’s protective clothing

Firefighters rely heavily on their firefighter’s protective clothing (FPC) for their safety. The effectiveness of an appropriately engineered turnout suit decreases over time when repeatedly exposed to radiative heat and flame. A measure of durability is the radiative protective performance (RPP) rating, which is influenced by properties like thickness, surface area, and areal density (mass per unit area) of outer shell fabric in multilayered ensembles. Four independent variables were considered: fabric material, pick density, exposure cycles and heat flux intensity. In addition to RPP, changes in the thickness, shrinkage, and mass loss was also tracked. An evaluation of properties was conducted at the end of each cycle to determine the effects of the heat flux (21, 42 and 63 kW/m2), number of exposure cycles (from one to five) and effects of each attribute. Two types of fabrics were used in this study, one made with meta aramid (Nomex® IIIA) yarns in both warp and weft (type-A fabric), and the other made with Nomex® IIIA (warp) and para aramid (Kevlar®) (weft) (type-B fabric). Type-A fabrics displayed a greater degree of differentiation in their properties than type-B fabrics. With the same exposure conditions, the thickness, shrinkage, mass loss and RPP gradually increased. A regression analysis conclusively established that pick density significantly affects the performance of the outer-shell fabric used in FPCs. Textile designers may find the results useful for creating more thermo-stable and durable turnout suits in the future.

Contamination and removal of polycyclic aromatic hydrocarbons in multilayered assemblies of firefighting protective clothing

Contaminants deposited on the firefighter protective clothing increase the risk of carcinogenesis by transdermal absorption. The effects of the inclination angle, waterproof grade, and fabric structure of the flame retardant outer layer of firefighting protective clothing on polycyclic aromatic hydrocarbon (PAH) contamination and laundering were studied by simulating smoking exposure. The permeation and transmission process of PAHs in multilayered assemblies were investigated. Results showed that the adsorption capacity of soot and PAH contamination on fabric with a water repellent finish relatively increased, and outer layer absorbed more PAHs at 180° compared to other inclination angles. The fabric structure with single layer had a strong adsorption capacity and low removal capacity for PAHs. The highest amount of PAH contaminant was found in the moisture barrier layer, and the removal rate (44.7%) was much lower than that of the outer layer cleaned through conventional laundering (91.3%). The research can better provide scientific support for pollution control and clothing cleaning in the actual firefight.

Durability of metallic coating for improvement of thermal protective performance of firefighter protective clothing

The objective of this study is to investigate the durability of metallic coating for firefighter protective clothing when subjected to different washing cycles. Firefighter clothing ensemble consists of three layers, i.e. outer shell, moisture barrier, and thermal liner. The exposed surface of the outer shell was coated with silver particles through the physical vapor deposition process also called Magnetron sputtering. Afterwards, these specimens were exposed to radiant heat transmission machine at 30 kW/m2 and 40 kW/m2, respectively. It was found that specimens coated with silver particles showed improved thermal protective performance as compared to uncoated specimens. Later on, silver-coated specimens undergo five cycles of washing and their thermal protective performance in terms of transmitted heat flux density Qc (kW/m2) and radiant heat transmission index (RHTI 24 and RHTI 12) was measured. It was found that after five washing cycles, there was a negligible decline in thermal protective performance when exposed to 40 kW/m2. Afterwards, bending moment and water vapor resistance properties were measured before and after five washing cycles. It was inferred that there was no considerable difference in bending moment and water vapor resistance after different washing cycles, which confirmed stability of silver coating layers. However, when silver-coated outer shells were evaluated for abrasion resistance, there was a substantial decline in thermal protective performance on exposure to 40 kW/m2 after one hundred to five hundred cycles of abrasion.

PAH contamination of firefighter protective clothing and cleaning effectiveness

The objective of this study was to determine the concentration of polycyclic aromatic hydrocarbons (PAHs) in firefighter protective clothing used under different conditions (fire suppression operations and live-fire enclosure simulations). Ultra-high performance liquid chromatography with fluorescence detection (UHPLC/FL) was applied to determine PAH content in the outer shell, moisture barrier (membrane), and thermal barrier layers of protective clothing. Analysis involved eight PAHs, with the total PAH concentration being strongly dependent on use conditions and clothing layer. The PAH concentration in clothing worn during fire suppression (43 ± 16–63 ± 26 μg g−1) was approx. 10–12 times higher as compared to that in clothing worn during live-fire simulation (4.0 ± 1.1–5.4 ± 1.4 μg g−1). The highest total PAH content (84 ± 41 μg g−1) was found in the membrane of clothing worn during fire suppression (approx. 50 times greater than in the case of live-fire simulation – 1.6 ± 0.99 μg g−1). Cleaning with the use of machine washing removed a considerable part of PAH contamination, with cleaning effectiveness ranging from 79 ± 14% for the outer shell, 63 ± 25% for the membrane to 58 ± 14% for the thermal barrier. Furthermore, in firefighter protective clothing worn during fire suppression operations higher PAH concentrations were detected in samples from the knee region as compared to those from the sleeves.

Smart coating in protective clothing for firefighters: An overview and recent improvements

Recently, new developments in the design and performance optimization of smart mechanisms associated with natural and man-made hazards have progressed considerably. This is mainly owing to advances in smart sensing mechanisms including communication and data technologies. This work provides a detailed overview of existing improvements on smart hazard monitoring equipment and materials applied in textile sensing systems. Given that fire is one of the most common disasters in many countries such as Australia, and every year many firefighters are affected by these unfortunate incidents, the focus of this study is on firefighters' protective clothing Fire Fighter Protective clothing. This review provides a unique opportunity to study smart sensing systems in coating technologies, potentially provides more effective techniques for training and better safety protocols of fire fighters. It aims to revisit the existing advances and address recent challenges and opportunities for improvement in the domain of smart coating and fire protective wearables. The goal of this review is to provide information about smart coating in protective clothing for firefighters. The capability of some of these clothing in managing thermal stresses, responding to humid environment, monitoring some critical parameters and adapting to the size of the wearers (clothes fabricated with phase change and shape memory substances) made them attractive choice in adjusting specific design features of industrial textiles. Various types of phase change and shape memory substances are defined and a combination of these substances within the structure of fabrics are presented. This paper also provides a detailed review on the heat exposure and capability of the shape memory substances (SMM) and phase change materials (PCM) to delay the heat transfer through fire fighter protective clothing. Referring to the former research, several issues have been detected using such substances. For instance, combination of phase change and shape memory materials needs fundamental improvements with regards to assessment techniques and testing criteria. Additionally, recent improvements in the domain of PCM and SMM including modifying mechanical features, functionality, and durability under different conditions have been informed. It has been suggested that the major problem in developing fabric-Phase Change Materials (PCMs) and Shape memory material (SMM) systems is their usage methods. At last recent developments on wearable monitoring systems applied in the firefighters’ protective gear. Wearable sensors are usually used directly on the body or located on wearable items to monitor information related to firefighters’ safety.

Impact of ultraviolet radiation on thermal protective performance and comfort properties of firefighter protective clothing

In this study, the impact of ultraviolet radiation is studied on thermal protective performance and clothing comfort properties of firefighter protective clothing. Firefighter clothing assembly consists of the outer shell, moisture barrier and thermal barrier. In this research, two different outer shells were utilized. Outer shell O1 consists of inherently fire- retardant fibres mainly consisting of Conex (Nomex) and firefighter assembly having Conex as the outer shell was called specimen A. On the other hand, clothing arrangement which employed Proban coated outer layer (O2) was termed as specimen B. Both specimens were evaluated for tensile testing, air permeability, radiant heat transmission machine, bending moment and water vapour resistance before and after exposure to ultraviolet radiation. The tensile strength value of outer shell O2 was higher than that of O1 before and after exposure to UV radiation. Tensile strength values of both outer shells O1 and O2 decline after exposure to ultraviolet radiation. Air permeability values of both outer shell O1 and O2 increase after being exposed to ultraviolet radiation. It was noted that specimen A has better thermal protective performance as compared to specimen B, before and after exposure to UV radiation. Also, radiant heat transmission index RHTI 24 values were greater for specimen A as compared to specimen B, before and after exposure to UV radiation. Moreover, bending moment values for both outer shell O1 and O2 decline after being subjected to UV radiation. Furthermore, Water vapour resistance values of outer shell O1 and outer shell O2 enhance after exposure to ultraviolet radiation.

Thermal Properties of Special New Generation Personal Protective Clothing for Firefighters-Rescuers

Every day, firefighters put their health and life at risk by saving people and their property not only during fires, but by being always ready during all kinds of unfortunate events. Therefore, they need special personal protective equipment, including protective clothing. The purpose of the study was to compare thermal properties of new (PROTON and SYRIUSZ) and old (US-03) personal protective clothing for firefighters. Measurements of thermal insulation (total, effective and local) were carried out using a full body shape thermal manikin Newton consisting of 34 segments, in which temperature and heat flux were controlled independently. Results of the total thermal insulation of the entire clothing reveal differences between all three models. The lowest values were noticed for the model PROTON with light and shorter jacket and the highest values of thermal insulation for the new model SYRIUSZ, indicating that this model protect the user against heat most effectively. New models of personal protective clothing for firefighters should be recommended for use in everyday work, because they are characterized by better parameters than the previous type of protective clothing, both in terms of thermal protection and mobility.

The impact of water on firefighter protective clothing thermal performance and steam burn occurrence in firefighters

Exposure to oscillating heat fluxes while having variable water contents in the thermal protective clothing (T.P.C) is possible in a real firefighting scenario. The occurrence of steam burns becomes inevitable in certain conditions which are still unidentified in the literature. In light of such, in this study, the effect of water distribution on thermal protective clothing (T.P.C) performance is studied for various environmental conditions (i.e., fixed and transient values of heat flux). A numerical approach is used to simulate heat and mass transport in the T.P.C.. Parametric studies are performed, where the exposure heat flux (0–80 kW/m2) and initial quantities of water in the T.P.C. are varied and correlated with second–degree burn times. The presence of water in the outer shell increases second-degree burn times, while water in the inner layer has the opposite effect for high heat fluxes. For the tested heat fluxes, burns obtained are majorly of a scald nature. The results generated allow for identifying environmental and protective clothing conditions where steam burns may become a potential hazard. This study can directly impact the proceedings for firefighters to take in certain environmental conditions and aid in the design of more effective firefighting protective suits.

284 Cognitive Deficits due to Insufficient Sleep are Mitigated Following Strenuous Physical Exertion in Firefighters

Abstract Introduction Insufficient sleep impairs cognitive function which results in costly errors. Firefighter shifts regularly exceed 24-hrs with little to no sleep. Nevertheless, firefighters must maintain and flexibly shift attention in high-pressure scenarios. Firefighters also engage in strenuous physical exertion during fire suppression activities. However, it is unclear whether physical exertion acts as another stressor, exasperating cognitive deficits due to insufficient sleep, or whether physical exertion enhances arousal to reduce cognitive deficits. Moreover, the effects of physical exertion may depend on the type of cognitive process and extent of sleep loss. We examined the effect of physical exertion on vigilant attention and task-switching in firefighters who underwent sleep-deprivation or sleep-disruption. Methods Participants were 17 healthy young adult males who participated in a within-subjects crossover design with three experimental lab visits: sleep-deprivation, sleep-disruption (woken 3 times for 60-min each), and normal sleep. The next day, participants completed a 50-min treadmill exercise task in a heated room in firefighter protective clothing. Participants completed a vigilant attention task (Psychomotor Vigilance Task, PVT) and a task-switching task five to nine times each visit. The five timepoints of interest–before and after the sleep manipulation night, before and after the treadmill exercise task, and recovery (approximately 180-min following exercise)–were examined using linear mixed effects models. Results We analyzed lapses (reaction times [RT]>500ms) on the PVT and switch-trial RT and accuracy on the task-switching task for sleep-deprivation and sleep-disruption conditions relative to normal sleep. Sleep-disruption, p=.001, and sleep-deprivation, p<.001, increased lapses. Sleep-disruption increased switch-trial RT, p=.01, and sleep-deprivation reduced switch-trial accuracy, p=.01. Only switch-trial accuracy improved immediately after the treadmill exercise task and only for the sleep-deprivation condition, p=.01. During recovery, lapses lessened for the sleep-deprivation condition, p=.049, and switch-trial accuracy improved for both sleep-deprivation, p=.01, and sleep-disruption conditions, p=.049. Conclusion Physical exertion reduced task-switching and attentional deficits caused by insufficient sleep, with more benefits observed during recovery. We found no evidence for performance decrements due to physical exertion. Physical exertion may interact with the extent of sleep loss–primarily benefitting performance under conditions of total sleep-deprivation. Support (if any) DSF Charitable Foundation and University of Pittsburgh Clinical and Translational Science Institute UL1TR001857.

Quantitative analysis of moisture distribution and transfer in firefighter protective clothing exposed to low-intensity radiation with/without hot steam

Objectives. This study aimed to examine moisture distribution and transfer in firefighter protective clothing when moisture from the atmosphere and skin sweat were considered simultaneously.Methods. A self-developed test apparatus was used to simulate moisture transfer through the protective clothing under exposure to thermal radiation. The weights of each layer of fabric before and after heat exposure were measured to analyze the moisture distribution and transfer. Results. The moisture level in each layer of fabric before the exposure presented an increase over the initial moisture content. After dry heat exposure, the moisture content in each layer of fabric reduced gradually. However, the existence of hot steam increased the moisture content stored in the fabric system and accelerated the moisture transmitting to the skin surface. In addition, the amount of outward water evaporation for dry heat exposure was moderately more than inward water evaporation, while the amount of inward water evaporation was greatly more than outward water evaporation for wet heat exposure. Conclusion. Moisture transfer in the firefighter protective clothing was a two-way transmission during both heat exposures. Understanding moisture transfer helps to provide proper guidance to improve the thermal protection of clothing and reduce steam burns.

Establishment of a digital simulated testing platform for radiation protection performance and preparation of three-layer coated flexible composites

Fire proximity suits serve as the highest level of thermal protective clothing for firefighters when passing through the scene of a fire and within close range of open fire. A digital simulated testing platform for radiation protection performance was established based on the TPP701D thermal protective performance tester, by comparison of simulated data and measured results for the outer material of the fire proximity suit. Using single-, double- and three-layer flexible composites and the fabric as the base material, the reliability of the established simulation test platform was investigated. Based on this simulated test platform, in this paper the influence of the material structure and performance parameters (thickness, thermal conductivity, specific heat, density, emission rate and thermal reflectivity) of the heat radiation layer possessed by the three types of coating (thermal radiation protective coating, fireproof heat insulated coating and heat insulating coating) of three-layer coated flexible composites are discussed, thus providing the theoretical basis for the optimization and preparation of alternative outer materials for fire proximity suits. Based on the simulation data and measured results, the radiation protection performance of the three-layer structure is enhanced. Improving the average reflectivity of the heat rays for the thermal radiation protective coating, increasing the thickness of the heat insulating coating and reducing the thermal conductivity of the heat insulating coating are effective means of improving the radiation protection performance of the three-layer coated flexible composites.