Search Results (1,085)

Recruitment of firefighters is, in part, hindered due to attrition from fire academies. This study explored initial fitness differences between those who graduated (GRAD) or were released (REL) from the academy. During the first week of the academy, recruits (N = 407; GRAD = 354, REL = 53; 26.6 ± 7.2 yrs; 177.6 ± 8.6 cm; 87.9 ± 17.2 kg) completed an assessment battery including: body composition using skinfold calipers to estimate percent body fat (BF) and fat-free mass (FFM); shoulder mobility via Apley’s scratch test (APLEY); aerobic fitness (VO_2peak) and heart rate recovery (HRR_1min) estimated from the five-minute Forestry step test; muscular strength via the sum of right and left handgrip (SHG); and muscular endurance via a paced two-minute push-up test (PU). A t-test identified age differences between GRAD and REL, followed by separate ANCOVAs for each fitness measure, and logistic regression to identify the ability of fitness measures to predict academy outcome. GRAD had a lower age and BF and a higher FFM, VO_2peak, SHG, and PU, but did not differ in APLEY or HRR_1min. The full model predicting release was significant; age, BF, and FFM were significant predictors. These results provide pre-fire academy preparation guidance for optimizing the potential for successful academy completion. Full article

To address challenges such as the sudden onset of urban fires, data synchronization delays in early warning systems, response lags, and insufficient routine monitoring, this paper proposes a Spatio-Temporal Collaborative Optimization for Joint Control and Scheduling (STCO-JCS) algorithm tailored for unmanned aerial vehicles (UAVs) and wireless sensor networks (WSNs). First, spatial autocorrelation analysis based on fire data classifies areas into ultra-high, high, medium, and low risk zones to assist in determining UAV access priorities. Second, we construct optimal inspection trajectories for the UAV by taking into account the inspection sequence and the city’s topography. By modeling the path deviations caused by wind interference and designing precision control algorithms, we improve the accuracy of the UAV’s flight path, ultimately achieving the goal of reducing UAV inspection time. Finally, by coordinating the spatiotemporal operations of drones and wireless sensor networks, we can achieve early detection and rapid response in high-risk fire zones, thereby reducing drone energy consumption while enhancing the efficiency of the UAV-WSN fire monitoring system. Simulation results demonstrate that under a 20-square-kilometer simulation area, STCO-JCS controls inspection paths within 14–17 km. In the multi-UAV scenario, the proposed method achieves approximately 3.17–9.66% improvement in energy efficiency, while in the single-UAV scenario, improvements of 10.83%, 50.54%, and 9.26% are observed in metrics. This provides effective decision support for the dynamic deployment of firefighting and rescue resources. Full article

Firefighters are regularly exposed to occupational stress and potentially traumatic events. However, few evidence-based, fire service-specific interventions exist. Brief, mindfulness-based interventions may help address these challenges by improving regulation skills and reducing psychological distress. This pilot randomized controlled trial primarily evaluated the feasibility and acceptability of a one-session, group-based, virtual mindful attention training workshop developed specifically for firefighters, with secondary evaluation of preliminary efficacy. Firefighters (N = 82) were recruited from multiple fire departments across a large U.S. Southwestern metropolitan area and randomized to the mindful attention workshop (n = 45) or a waitlist control condition (n = 37). Feasibility outcomes were mixed, with strong enrollment among eligible participants (74.5%) but relatively low workshop attendance among those randomized to the intervention (53.3%). A total of 24 firefighters completed the workshop and found it to be helpful, informative, and relevant to the challenges faced in the fire service, with group processes characterized by high comfort, understanding, and low conflict. However, no significant between-group differences were observed in reductions in symptom severity or increases in mindfulness-based outcomes. Post hoc descriptive analyses revealed that most firefighters expressed strong interest in digitally delivered mental health content and the vast majority perceived online or app-based firefighter-specific mental health resources as helpful. Findings indicate mixed feasibility, strong acceptability among attendees, and a lack of preliminary efficacy, and highlight directions for refining intervention delivery of this pilot workshop and evaluating clinical impact in future trials. Full article

The purpose of this study was to quantify the degree to which personal protective equipment (PPE) affects the core–skin temperature gradient in nine recruit firefighters attending fire academy. Participants wore a chest monitor and ingested a pill to continually measure skin and core temperature, respectively. PPE status was defined as periods during which participants were wearing full PPE (ON) and not wearing PPE (OFF). During the study, participants transitioned between PPE ON to PPE OFF seven times. These transition timepoints, defined as paired two-minute averages collected immediately before (PPE OFF) and shortly after (PPE ON) donning PPE, were analyzed to examine the immediate effects of PPE use. Factorial repeated-measures ANOVAs were used to assess the effects of PPE status, time, and their interaction on temperature gradient, core temperature, and skin temperature. There was a significant interaction effect on the temperature gradient (p < 0.001), with higher gradients in the OFF condition compared to ON at timepoints 2–7. A significant interaction was observed for skin temperature with higher values in ON than OFF for timepoints 2–7 as well. There was no interaction (p = 0.445) or main effect of PPE status (p = 0.906) for core temperature. This study demonstrates that adding PPE significantly reduced the core–skin temperature gradient in recruit firefighters, largely due to increases in skin temperature. Full article

Aerial forest firefighting is a critical technology for wildfire suppression. Recent studies have examined suppression agent drop dynamics, deposition patterns, and optimization strategies. This review synthesizes advances from three perspectives: (i) in-flight suppression agent jet dynamics, (ii) ground deposition patterns, and (iii) suppression effectiveness, while outlining future research directions. Flight altitude, velocity, and momentum ratio govern jet behavior—affecting penetration, expansion, and breakup. Momentum ratio, shaped by drop velocity and aircraft speed, is pivotal in penetration depth and fragmentation. Deposition patterns vary with delivery systems and flight parameters: low-altitude/low-speed drops yield higher coverage density over smaller areas, whereas high-altitude/high-speed drops cover larger areas but less densely. Suppression efficacy depends on fire intensity–vegetation interactions, droplet size–coverage requirements, and operational parameters such as response time, aircraft capacity, and real-time intelligence. Large droplets excel in cooling high-intensity flames, while fine droplets provide efficient area coverage. Adequate resources and integrated data enhance outcomes. Future work should couple multi-physics models of terrain, meteorology, and fire plume dynamics, and develop integrated deposition models including wind, thermodynamics, terrain, and fire behavior to optimize aerial dispersion in diverse wildfire scenarios. Full article

The recycling of technical textile waste represents a major challenge due to the complex and multilayered structure of these materials. Firefighter protective clothing, mainly composed of high-performance aramid fibers combined with polymeric membranes and auxiliary textile components, is commonly landfilled or incinerated at the end of its service life, resulting in a significant environmental impact. This work utilized recycled aramid-rich textile waste obtained from end-of-life firefighter protective clothing as reinforcement for polyamide 6 to develop high-performance thermoplastic composites within a circular economy framework. Composites containing 15, 30, 45, and 60 wt.% of recycled textile waste were manufactured by melt compounding followed by injection molding. In addition, a selected formulation containing 30 wt.% reinforcement was compatibilized using an amino-functional silane to improve interfacial adhesion. The materials were systematically characterized in terms of tensile properties, thermal behavior, thermomechanical performance, water uptake, flammability, colorimetric properties, and fracture morphology by field emission scanning electron microscopy. The results revealed a pronounced increase in stiffness and thermomechanical stability, with tensile strength increasing from approximately 65 MPa for neat PA6 up to 78 MPa at 30 wt.% reinforcement, and elastic modulus exceeding 5000 MPa at high reinforcement contents. An optimal balance between mechanical performance and ductility was achieved at 30 wt.% reinforcement, while higher contents enabled a substantial extension of the service temperature range, with HDT values increasing from 55 °C for neat PA6 up to 173 °C for highly reinforced systems. FESEM analysis confirmed improved interfacial adhesion in silane-compatibilized systems, explaining the enhanced mechanical and thermomechanical behavior. Furthermore, the incorporation of recycled aramid-rich textile waste led to a significant improvement in flame retardancy, enabling UL-94 V-0 classification at 30 wt.% reinforcement and above, without the use of additional flame-retardant additives, enabling UL-94 V-0 classification without additional flame-retardant additives. Overall, this study demonstrates the technical feasibility and high added-value potential of valorizing firefighter protective clothing waste into advanced PA6-based composites with enhanced mechanical, thermal, and fire-resistant properties, providing a sustainable route for the valorization of high-performance textile waste. Full article

Background/Objectives: Dietary approaches to combating risk factors for cardiovascular disease are valuable, especially for individuals in high-stress occupations like first responders. The purpose of this pilot randomized control trial was to determine the effect of regular peanut butter (PB) supplementation on blood pressure and primary measures of body composition (body fat %, fat mass, and lean mass) in firefighters. Methods: Full-time firefighters (N = 40; 1 woman) were randomly assigned to a control group or a peanut butter group for 7 weeks. Participants in the peanut butter group consumed one serving of peanut butter before bed at least 5 days per week for the intervention period. Participants in the control group continued with their usual diet. Indices of body composition and blood pressure were collected before and after the intervention period and compared using mixed-factorial ANOVAs (α = 0.05). Results: No interaction effects between group and time were observed for blood pressure variables (p = 0.619–0.650). Similarly, the changes among the PB group over time in percent body fat (Δ = −0.53 ± 1.74%), fat mass (Δ = −0.73 ± 2.21 kg), and lean body mass (Δ = 0.04 ± 1.65 kg) were not significantly different than the changes over time in the control group (p ≥ 0.067 for all). Conclusions: Seven-week PB supplementation did not affect male firefighter body composition or blood pressure; however, future studies should investigate longer durations with sophisticated dietary recall methods. ClinicalTrials.gov Identifier: NCT06364202. Full article

With the increasing complexity of wildfire emergency response, the aerial emergency response system is imposing increasing demands on both safety and decision rationality of takeoff and landing site selection. Site selection decisions are influenced by multi-dimensional factors, including geographical location, meteorological factors, and operational safety considerations, resulting in a pronounced coupling of multiple factors in the decision-making process. However, existing studies primarily focus on spatial suitability evaluation or technical implementation, often relying on predefined indicator systems and independence assumptions, while lacking a systematic characterization of the influencing factor system and its interrelationships in takeoff and landing site selection. To address this gap, this study proposes a novel structured decision-making framework to systematically analyze and optimize the selection of takeoff and landing sites for bucket firefighting helicopters in wildfire aerial emergency response scenarios. First, a procedural grounded theory approach is employed to systematically identify the influencing factors associated with site selection, thereby constructing a traceable decision-making factor system. Second, fuzzy DEMATEL is applied to model the causal relationships and structural interdependencies among these factors. Finally, a cumulative contribution rate based on centrality is introduced to screen and optimize the decision indicators, resulting in a refined set of key decision indicators. The results reveal the structural roles of different influencing factors in site selection, reduce the reliance on experience-driven judgment, and reconceptualize the problem from traditional indicator weighting and ranking into a structured decision-making process involving multi-factor coupling. This provides systematic decision support for takeoff and landing site selection in wildfire aerial emergency response and establishes a foundation for subsequent spatial suitability analysis and case-based validation. Furthermore, the results are consistent with expert experience and practical operational constraints, indicating the potential applicability of the proposed method in real-world decision-making. Full article

Fire trucks equipped with truck-mounted electric water cannons are key mobile firefighting assets for urban and industrial fire response. However, due to the inherent mechanical inertia of the cannon body, its low-frequency motion response cannot match high-frequency control commands, making the system prone to oscillations and control instability. To address this command–execution frequency mismatch, this paper proposes a decoupled dual closed-loop control architecture for truck-mounted electric water cannons on mobile fire trucks: the fast loop is used for fire-source tracking and rapid localization, while the slow loop is used for water-jet aiming alignment. In the fast loop, a 2-D quadrant positioning rule drives the pan–tilt unit to achieve rapid fire tracking and accurate centering. In the slow loop, Kalman-filter-based state estimation and delay-aligned prediction generate feedforward aiming commands; these commands are fused with error feedback and further processed through command limiting and trajectory optimization, ultimately producing smooth and executable angle references. The visual perception module ran at 58 FPS, satisfying the real-time requirement of the proposed system. In five repeated extinguishment tests under controlled open-site conditions, the proposed method successfully completed all trials and reduced the mean extinguishment time to 13.55 s, compared with 15.83 s for the incremental-PID baseline and 23.76 s for the coupled proportional baseline, while also showing smoother correction and less redundant oscillation. Full article

Firefighters must locate victims reliably to carry out rescue operations within burning structures during urban firefighting events. Low visibility, reduced oxygen levels, weakened structural rigidity, and dense smoke make it difficult to locate victims. In addition to these challenges, victims may be unconscious and unable to report their locations to firefighters. This research work explores the Double Deep Q-Network (Double DQN), Dueling Deep Q-Network (Dueling DQN), and Dueling Double Deep Q-Network (D3QN) agents for an unmanned aerial vehicle (UAV) to navigate around a structure and locate trapped victims within it. The UAV’s position, Light Detection and Ranging (LiDAR), and infrared camera data are utilized as inputs for the Deep Q-Networks. The PER is used to store transitions and sample them according to priority for training. Python’s Pygame library is used in this research to create a simulated environment in which infrared camera and LiDAR data are simulated. The performance of the UAV agent is evaluated using cumulative maximum reward, reward distribution histogram, Temporal Difference (TD) error over time, and number of successful episodes. Among the three DQN UAV agents, the Dueling DQN and Double DQN have potential for real-world applications in firefighting. Full article

In fire emergency ventilation systems, EC (Electronically Commutated) internal-rotor axial fans are critical devices, but their high-speed operation generates aerodynamic noise often exceeding 90 dB (A). While struts are core structural components regulating flow field stability, their specific geometric impact on trailing-edge vortex shedding and noise generation mechanisms remains unclear. This study investigates three strut configurations: a hexagonal annular type, a hexagonal double-ring type, and a three-pronged type. A coupled numerical model was established using Large Eddy Simulation (LES) and the Ffowcs Williams and Hawkings (FW-H) acoustic analogy. The Q-criterion was employed to analyze vortical structures, with numerical predictions validated against experimental measurements in a semi-anechoic chamber. The results quantitatively demonstrate that optimizing the strut geometry significantly mitigates unsteady flow separation. The three-pronged strut (Model C) effectively dispersed high-velocity airflow, reducing the peak turbulent kinetic energy (TKE) at the inlet by 30% compared to the original design (Model a). Furthermore, Model C achieved a 6.7 dB reduction in the sound pressure level at the blade-passing frequency (BPF), alongside a 14.1% reduction in pressure pulsation amplitude near the blade tip. Structural optimization of struts enables synergistic control over turbulence distribution and pressure fluctuations. By disrupting the phase coherence of shed vortices, the optimized design fundamentally suppresses aerodynamic noise, advancing axial fan design toward precise quantitative aeroacoustic optimization. Full article

Background/Objectives: Survival after out-of-hospital cardiac arrest (OHCA) is strongly influenced by the no-flow interval—the time between cardiac arrest and initiation of cardio-pulmonary resuscitation (CPR)—with the probability of good neurological outcome decreasing by 13% per minute without circulation. Rapid mobilization of all available responders is therefore critical. Fire services, due to their widespread local presence, can shorten response times, but turnout times—particularly in departments staffed with volunteers—may limit their benefit. In sparsely populated regions, dual dispatch of emergency medical service (EMS) and fire services may help reduce arrival times and thus improve outcomes. Methods: Response times to 1000 hypothetical OHCAs in Lower Austria (19,000 km², 1.73 million population) were modelled. Travel times were calculated from 121 EMS stations and 1590 fire stations using the fastest route. Turnout times were set at two minutes for EMS and five minutes for fire services, with a sensitivity analysis for eight minutes for fire services. For each event, the shortest travel time was compared for both single EMS and dual EMS and fire service dispatch. Results: Mean response time was 10.6 min (SD 4.7) for EMS alone vs. 7.2 min (SD 2.2) with dual dispatch (p < 0.0001). At the 90th percentile, times were 16.8 vs. 9.7 min. Within 10 min, 49.0% of cases were reached by EMS alone vs. 92.6% with dual dispatch; fire services arrived first in 62.7% of all simulations. With an 8 min turnout, mean dual-dispatch arrival increased to 8.8 min (SD 2.9), with 68.2% of all patients reached within 10 min and firefighters arriving first in 42.9%. Conclusions: Dual dispatch of fire services and EMS significantly reduced response times, particularly in areas with a low population density. Using a dual dispatch strategy, response times were below 10 min in nearly all of the patients. Full article

Object detection in UAV-based fire rescue scenarios faces multiple challenges, including densely distributed small targets, severe occlusion, and interference from smoke and flames. Existing mainstream detection models, such as the YOLO series, often prioritize inference speed at the expense of modeling global context and spatial positional information, resulting in limited performance in such complex environments. To address these limitations, this paper proposes FirePM-YOLO, an object detection architecture optimized for fire rescue applications. Based on the YOLO framework, the proposed model introduces two key innovations: first, a Position-Aware Enhanced Mamba module (PEMamba) is designed, which incorporates a compact positional encoding mechanism, lightweight spatial enhancement, and an adaptive feature fusion strategy to significantly improve scene perception while maintaining computational efficiency. Second, a PEMBottleneck structure is constructed, which dynamically balances local convolutional features and global PEMamba features via learnable weights. This module is embedded into the shallow layers of the backbone network, forming an enhanced PEM-C3K2 module that captures long-range dependencies with linear complexity while preserving fine local details, thereby enabling holistic contextual understanding of fireground environments. Experimental results on the self-built “FireRescue” dataset demonstrate that compared with the original YOLOv12 and other mainstream detectors, the proposed model achieves improvements in both mean average precision (mAP) and recall while maintaining real-time inference capability. Notably, it exhibits superior detection performance on challenging samples, such as small-scale and partially occluded professional firefighting vehicles. Full article

Posttraumatic stress disorder (PTSD) has been linked to impaired physical function, which in turn predicts falls, morbidity, and mortality. However, few studies have used objective measures such as handgrip strength to assess physical function. In this cross-sectional study, we investigated associations of average PTSD symptom severity and symptom domain severity with measures of maximum handgrip strength and handgrip asymmetry from 11/2021–12/2023, among 381 male firefighters and emergency medical responders who responded to the World Trade Center disaster, using covariate-adjusted linear regression models. PTSD was diagnosed using the Structured Clinical Interview for the DSM-5 in 17% of responders. Greater overall PTSD average symptom severity was associated with weaker maximum handgrip strength (β = −4.43 lbs; 95%; CI: −8.77, −0.09; p = 0.045). Higher re-experiencing symptom severity was associated with weaker maximum handgrip strength (β = −4.17 lbs; 95% CI: −8.13, −0.22; p = 0.039). Avoidance symptoms were associated with weaker handgrip strength in adjusted models (β = −4.14 lbs; 95% CI: −7.56, −0.73; p = 0.018), and associated with a larger negative difference assessing for hand asymmetry (β = −2.20 lbs; 95% CI: −4.18, −0.22; p = 0.029). Findings suggest that PTSD may contribute to long-term physical decline, even in populations with high baseline fitness. Full article

This study describes participants’ views and insights into crafting effective communication aimed at smokeless tobacco and nicotine pouch prevention among fire academy trainees and new recruits. Firefighters have elevated rates of smokeless tobacco use compared with the general population. Nicotine pouches have also gained popularity among this occupational group. We launched a pilot project centered in rural Northern California counties to uncover factors that can be used to communicate smokeless tobacco and nicotine pouch prevention messages within the firefighter workplace. As a first step, we conducted semi-structured interviews with firefighter subject matter experts, including fire chiefs, fire academy instructors, wildlands firefighters, and recent fire academy graduates. This purposive sample (n = 13) was obtained through referrals from the project’s Community Advisory Board, composed of fire service professionals. Interviews were audio recorded and transcribed. Next, the qualitative interviews were thematically analyzed. The results focus on two aspects of effective workplace communication in the service to delivery of smokeless tobacco and nicotine pouch prevention messages: content (core information conveyed in a message), and format (how the message is transmitted or displayed). Examples of the former are the importance of keeping oneself healthy so that one can do one’s job; do not risk a future compensation claim due to smokeless tobacco or nicotine pouch use. Examples of the latter are the use of brevity; humor. Because firefighters often initiate use of these products after they join the fire service, communicating prevention messages in the workplace during the firefighter training and recruitment stage may help disrupt the uptake of nicotine products. Full article