The UK VIRTUS helmet: User feedback from Operation TORAL in Afghanistan.

In 2015, the VIRTUS helmet was introduced to UK Armed Forces and will ultimately replace the Mark 7 combat helmet. The VIRTUS helmet has a reduced trimline compared to the Mark 7 helmet and can incorporate attachments such as a visor, mandible guard and nape protection. An anonymous questionnaire was provided to 200 UK Armed Forces personnel deployed to four locations on Operation TORAL in Afghanistan between September and October 2019. This is the first User feedback survey assessing the VIRTUS helmet in an operational environment. Users were measured to ascertain the fit of their helmet and asked to rate perceived helmet mass and comfort using a 5-point Likert scale. Users were also asked whether the VIRTUS helmet was better than previous helmets and about their use of the nape protection. The VIRTUS helmet was perceived to be an improvement over previously issued UK combat helmets in terms of both comfort and mass.

Applying the PTSD Checklist-Civilian and PTSD Checklist for DSM-5 crosswalk in a traumatic brain injury sample: A veterans affairs traumatic brain injury model systems study.

This study evaluates the use of the crosswalk between the PTSD Checklist-Civilian (PCL-C) and PTSD Checklist for DSM-5 (PCL-5) designed by Moshier et al. (2019) in a sample of service members and veterans (SM/V; N = 298) who had sustained a traumatic brain injury (TBI) and were receiving inpatient rehabilitation. The PCL-C and PCL-5 were completed at the same time. Predicted PCL-5 scores for the sample were obtained according to the crosswalk developed by Moshier et al. We used three measures of agreement: intraclass correlation coefficient (ICC), mean difference between predicted and observed scores, and Cohen's κ to determine the performance of the crosswalk in this sample. Subgroups relevant to those who have sustained a TBI, such as TBI severity, were also examined. There was strong agreement between the predicted and observed PCL-5 scores (ICC = .95). The overall mean difference between predicted and observed PCL-5 scores was 0.07 and not statistically significant (SD = 8.29, p = .89). Significant mean differences between predicted and observed PCL-5 scores calculated between subgroups were seen in Black participants (MD = -4.09, SD = 8.41, p = .01) and those in the Year 5 follow-up group (MD = 1.77, SD = 7.14, p = .03). Cohen's κ across subgroups had a mean of κ = 0.76 (.57-1.0), suggesting that there was moderate to almost perfect diagnostic agreement. Our results suggest the crosswalk created by Moshier et al. can be applied to SM/V who have suffered a TBI. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The nature and impacts of deployment-related encounters with children among Canadian military Veterans: a qualitative analysis.

Background: As armed conflict grows increasingly complex, the involvement of children in armed violence across diverse roles is rising. Consequently, military personnel are more likely to encounter children during deployment. However, little is known about deployment-related encounters with children and their impact on the mental health of military personnel and Veterans.Objective: This study qualitatively examines the nature and impacts of deployment-related encounters with children.Methods: We conducted semi-structured interviews with 16 Canadian Armed Forces Veterans, eliciting rich information on the nature of child encounters on deployment, the psycho-social-spiritual impacts of these encounters, and perceptions of support. Interview transcripts were analysed using thematic analysis.Results: Six primary themes were identified: types of encounters (i.e. factual aspects of deployment-related encounters with children), contextual factors (i.e. aspects of the mission, environment, and personal context relevant to one's experience of the encounter), appraisals of encounters (i.e. sensory or sense-making experiences relevant to the encounter), impacts of encounters (i.e. psycho-social, existential, and occupational impacts), coping strategies engaged in both during and after deployment, and support experiences, describing both formal and informal sources of support.Conclusions: Encounters with children are diverse and highly stressful, resulting in impacts pertinent to mental health, including psychological and moral distress, and difficulties with identity, spirituality, and relationships. These impacts are prompted by complex interactions among appraisals, expectations of morality, cultural norms, and professional duties and are amplified by various personal factors (e.g. childhood maltreatment history, parenthood), feelings of unpreparedness, and lack of post-deployment support. Implications for prevention, intervention, and policy are discussed with the aim of informing future efforts to safeguard and support military personnel facing a high likelihood of encounters with children.

Deployment-related encounters with children result in diverse impacts, including psychological and moral distress, along with disruptions in identity, spirituality, and interpersonal relationships.Encounters with children during military deployments are diverse and highly stressful, characterized by complex interactions among appraisals and expectations of morality, cultural norms, and professional duties.Emphasis on feeling unprepared for encounters with children highlights the need for future efforts to safeguard and support military personnel facing such situations.

Service Dogs for Veterans and Military Members With Posttraumatic Stress Disorder: A Nonrandomized Controlled Trial.

Importance: Military members and veterans (hereafter, veterans) with posttraumatic stress disorder (PTSD) increasingly seek psychiatric service dogs as a complementary intervention, yet the effectiveness of service dogs is understudied. Objective: To estimate the associations between psychiatric service dog partnership and self-reported and clinician-rated PTSD symptom severity, depression, anxiety, and psychosocial functioning after 3 months of intervention among veterans. Design, Setting, and Participants: This nonrandomized controlled trial used standardized and validated assessment instruments completed by participants and administered by blinded clinicians. Recruitment, eligibility screening, and enrollment were conducted between August 2017 and December 2019. Veterans were recruited using the database of an accredited nonprofit service dog organization with constituents throughout the US. Participants were veterans with a PTSD diagnosis; they were allocated to either the intervention group (n = 81) or control group (n = 75). Outcome assessments were performed at baseline and at the 3-month follow-up. Data analyses were completed in October 2023. Interventions: Participants allocated to the intervention group received a psychiatric service dog for PTSD, whereas those allocated to the control group remained on the waiting list based on the date of application submitted to the service dog organization. Both groups had unrestricted access to usual care. Main Outcomes and Measures: The primary outcomes were PTSD symptom severity, depression, and anxiety after 3 months, and the secondary outcomes were psychosocial functioning, such as quality of life and social health. The self-reported PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) was used to measure symptom severity, and the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) was used to assess PTSD diagnosis (score range for both instruments: 0-80, with higher scores indicating greater PTSD symptoms). Results: The 156 participants included in the trial had a mean (SD) age of 37.6 (8.3) years and included 117 males (75%), 17 Black or African American individuals (11%), 30 Hispanic individuals (19%), and 117 White individuals (76%). Compared with the control group, the intervention group had significantly lower PTSD symptom severity based on the PTSD Checklist for DSM-5 mean (SD) score (41.9 [16.9] vs 51.7 [16.1]; difference in means, -11.5 [95% CI, -16.2 to -6.6]; P < .001) and the CAPS-5 mean (SD) score (30.2 [10.2] vs 36.9 [10.2]; difference in means, -7.0 [95% CI, -10.8 to -4.5]; P < .001) at 3 months. The intervention group also had significantly lower depression scores (odds ratio [OR], 0.45 [95% CI, 0.23-0.86]; difference in means, -3.3 [95% CI, -6.8 to -0.6]), anxiety (OR, 0.25 [95% CI, 0.13-0.50]; difference in means, -4.4 [95% CI, -6.9 to -2.1]), and most areas of psychosocial functioning (eg, social isolation: OR, 0.34 [95% CI, 0.18-0.64]). Conclusions and Relevance: This nonrandomized controlled trial found that compared with usual care alone, partnership with a trained psychiatric service dog was associated with lower PTSD symptom severity and higher psychosocial functioning in veterans. Psychiatric service dogs may be an effective complementary intervention for military service-related PTSD. Trial Registration: ClinicalTrials.gov ID: NCT03245814.

U.S. Army mortality surveillance in active duty soldiers, 2014-2019.

Mortality surveillance is an important activity for capturing information on a population's health. This retrospective surveillance analysis utilizes administrative data sources to describe active duty U.S. Army soldiers who died from 2014 to 2019, and calculate mortality rates, assess trends by category of death, and identify leading causes of death within subpopulations. During the surveillance period, 2,530 soldier deaths were reported. The highest crude mortality rates observed during the 6-year surveillance period were for deaths by suicide, followed by accidental (i.e., unintentional injury) deaths. The crude mortality rates for natural deaths decreased significantly over the 6-year period, by an average of 6% annually. The leading causes of death were suicide by gunshot wound, motor vehicle accidents, suicide by hanging, neoplasms, and cardiovascular events. Significant differences were observed in the leading causes of death in relation to demographic characteristics, which has important implications for the development of focused educational campaigns to improve health behaviors and safe driving habits. Current public health programs to prevent suicide should be evaluated, with new approaches for firearm safety considered.

Outbreak of influenza and SARS-CoV-2 at the Armed Forces of the Philippines Health Service Education and Training Center, September 25-October 10, 2023.

In the last week of September 2023, a surge of influenza-like illness was observed among students of the Armed Forces of the Philippines (AFP) Health Service Education and Training Center, where 48 (27 males and 21 females; age in years: mean 33, range 27-41) of 247 military students at the Center presented with respiratory symptoms. Between September 25 and October 10, 2023, all 48 symptomatic students were evaluated with real-time reverse transcription polymerase chain reaction and sequencing for both influenza and SARS-CoV-2. Thirteen (27%) students were found positive for influenza A/H3 only, 6 (13%) for SARS-CoV-2 only, and 4 (8%) were co-infected with influenza A/H3 and SARS-CoV-2. Seventeen influenza A/ H3N2 viruses belonged to the same clade, 3C.2a1b.2a.2a.3a, and 4 SARSCoV-2 sequences belonged to the JE1.1 lineage, indicating a common source outbreak for both. The influenza A/H3N2 circulating virus belonged to a different clade than the vaccine strain for 2023 (3C.2a1b.2a.2a). Only 4 students had received the influenza vaccine for 2023. In response, the AFP Surgeon General issued a memorandum to all military health institutions on October 19, 2023 that mandated influenza vaccination as a prerequisite for enrollment of students at all education and training centers, along with implementation of non-pharmaceutical interventions and early notification and testing of students exhibiting influenza-like-illness.

Photorefractive Keratectomy in Experienced U.S. Naval Aviators: A Prospective Evaluation.

PURPOSE: To report on the prospective evaluation of photorefractive keratectomy (PRK) in experienced ametropic naval aviators that led to the approval of refractive surgery for military pilots. METHODS: This was the first study evaluating refractive surgery in naval aviators. Return to flight status after PRK and clinical outcomes and subjective and objective flight performance were evaluated. RESULTS: A total of 785 U.S. naval aviators were enrolled in the study. Average preoperative refraction was -2.92 ± 1.73 diopters (D) (range: +5.25 to -9.13 D). By 6 months, 85.9% of eyes were within ±0.50 D and 96.4% were within ±1.00 D of emmetropia. 94.4% of eyes achieved 20/20 or better, 74.3% had 20/16 or better, and 45.2% had 20/12.5 or better uncorrected distance visual acuity (UDVA) at 6 months. A total of 78.5% of aviators met return-to-flight criteria by 4 weeks, 83.3% by 8 weeks, and 90.8% by 12 weeks following PRK. All aviators eventually returned to full flight status. Cumulative flight experience included logging more than 48,000 flight hours and 19,500 landings in the 6 months following PRK. Psychometric questionnaire results showed that 78% reported improved ability to detect other aircraft and 92% reported improved ability to land on an aircraft carrier (82% significantly improved) compared to wearing corrective lenses. No one felt their vision was worse in these dynamic environments. All aviators indicated they would undergo the procedure again and would recommend it to a fellow aviator. CONCLUSIONS: This prospective study in U.S. naval aviators determined PRK to be safe and effective in a unique patient population operating in a visually demanding and hazardous environment. The program continues to be enthusiastically supported by aviators and PRK is now allowed in all branches of the military and for National Aeronautics and Space Administration astronauts. [J Refract Surg. 2024;40(6):e371-e380.].

Neuropsychological Profiles of Deployment-Related Mild Traumatic Brain Injury: A LIMBIC-CENC Study.

BACKGROUND AND OBJECTIVES: Traumatic brain injury (TBI) is a concern for US service members and veterans (SMV), leading to heterogeneous psychological and cognitive outcomes. We sought to identify neuropsychological profiles of mild TBI (mTBI) and posttraumatic stress disorder (PTSD) among the largest SMV sample to date. METHODS: We analyzed cross-sectional baseline data from SMV with prior combat deployments enrolled in the ongoing Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study. Latent profile analysis identified symptom profiles using 35 indicators, including physical symptoms, depression, quality of life, sleep quality, postconcussive symptoms, and cognitive performance. It is important to note that the profiles were determined independently of mTBI and probable PTSD status. After profile identification, we examined associations between demographic variables, mTBI characteristics, and PTSD symptoms with symptom profile membership. RESULTS: The analytic sample included 1,659 SMV (mean age 41.1 ± 10.0 years; 87% male); among them 29% (n = 480) had a history of non-deployment-related mTBI only, 14% (n = 239) had deployment-related mTBI only, 36% (n = 602) had both non-deployment and deployment-related mTBI, and 30% (n = 497) met criteria for probable PTSD. A 6-profile model had the best fit, with separation on all indicators (p < 0.001). The model revealed distinct neuropsychological profiles, representing a combination of 3 self-reported functioning patterns: high (HS), moderate (MS), and low (LS), and 2 cognitive performance patterns: high (HC) and low (LC). The profiles were (1) HS/HC: n=301, 18.1%; (2) HS/LC: n=294, 17.7%; (3) MS/HC: n=359, 21.6%; (4) MS/LC: n=316, 19.0%; (5) LS/HC: n=228, 13.7%; and (6) LS/LC: n=161, 9.7%. SMV with deployment-related mTBI tended to be grouped into lower functioning profiles and were more likely to meet criteria for probable PTSD. Conversely, SMV with no mTBI exposure or non-deployment-related mTBI were clustered in higher functioning profiles and had a lower likelihood of meeting criteria for probable PTSD. DISCUSSION: Findings suggest varied symptom and functional profiles in SMV, influenced by injury context and probable PTSD comorbidity. Despite diagnostic challenges, comprehensive assessment of functioning and cognition can detect subtle differences related to mTBI and PTSD, revealing distinct neuropsychological profiles. Prioritizing early treatment based on these profiles may improve prognostication and support efficient recovery.

Unravelling social status in the first medieval military order of the Iberian Peninsula using isotope analysis.

Medieval Iberia witnessed the complex negotiation of religious, social, and economic identities, including the formation of religious orders that played a major role in border disputes and conflicts. While archival records provide insights into the compositions of these orders, there have been few direct dietary or osteoarchaeological studies to date. Here, we analysed 25 individuals discovered at the Zorita de los Canes Castle church cemetery, Guadalajara, Spain, where members of one of the first religious orders, the Order of Calatrava knights, were buried between the 12th to 15th centuries CE. Stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of bone collagen reveal dietary patterns typical of the Medieval social elite, with the Bayesian R model, 'Simmr' suggesting a diet rich in poultry and marine fish in this inland population. Social comparisons and statistical analyses further support the idea that the order predominantly comprised the lower nobility and urban elite in agreement with historical sources. Our study suggests that while the cemetery primarily served the order's elite, the presence of individuals with diverse dietary patterns may indicate complexities of temporal use or wider social interaction of the medieval military order.

Comparison of different periodization models on isotonic and isokinetic muscle strength and lean mass in tactical athletes.

INTRODUCTION: Tactical athletes need to develop strength and lower limb lean mass (LL LM) to perform effectively. Resistance training (RT) is the most effective way to achieve these goals. Two periodization models stand out: traditional linear periodization (TLP) and daily undulating periodization (DUP). OBJECTIVE: To verify the effect of lower limb RT with TLP and DUP on isotonic and isokinetic muscle strength and lean mass in tactical athletes. METHOD: Thirty-five Brazilian Army military (21.57 ± 2.02 years; 81.81 ± 11.19 Kg; 177.79 ± 6.88 cm) were divided into two treatment groups and one active control group. INTERVENTIONS: The treatment groups performed 9 weeks of supervised RT (18 sessions), consisting of free weight exercises in this order: back squat, squat lunge, deadlift, and stiff legged deadlift. Dynamic isotonic muscle strength, lean mass, and isokinetic knee extension and flexion were assessed at baseline and post treatment period. RESULTS: There was a significant pre-post difference in dynamic isotonic muscle strength (TLP, P < 0.001; DUP, P < 0.001) and lean mass (TLP, P = 0.034; DUP, P = 0.003) of LL LM in both treatment groups. However, effect sizes (ES) and variations (%Δ) of gains were greater in the DUP group both in muscle strength (TLP, ES = 1.55, %Δ = 30.97; DUP, ES = 2.55, %Δ = 36.02), and in lean mass (TLP, ES = 0.13, %Δ = 2.07; DUP, ES = 0.44, %Δ = 2.95). For isokinetic knee flexion strength, a significant difference was found between the TLP versus CON. CONCLUSION: Both lower limb RT periodization models provided gains in muscle strength and lean mass, with a small advantage for the DUP approach. In the isokinetic knee flexion strength, the TLP was more effective.

Tropicalizing the Portable Radio: Electronics and the U.S. Military's Battle against Fungi in the Pacific War.

As the U.S. military became embroiled in "jungle warfare" across the Pacific during World War II, it was caught off guard by the rapid deterioration of materials and equipment in the tropics, where the air was hot, humid, and teeming with fungal spores. This article tells the story of how American scientists and engineers understood the "tropical deterioration" of portable radios and electronics and developed techniques to counteract it. Examining scientific efforts to prevent tropical decay reveals how exposure to tropical conditions during World War II shaped the development of portable electronics. Contributing to envirotech history and environmental media studies, this article uncovers the importance of climate proofing to the history of electronics miniaturization. Tropical deterioration, furthermore, provides a technology-focused lens for enriching our historical understanding of the tropics as an environmental imaginary.

How to Design a (Cybernetic) Revolution: Chileans Remember Salvador Allende's Techno-Utopian Project.

The recent commemoration of the fiftieth anniversary of the military coup led by General Augusto Pinochet offered an opportunity to explore unknown aspects of daily life before and during the dictatorship. This essay focuses on one particular exhibition (How to Design a Revolution: The Chilean Road to Design), which featured a complete reconstruction of the Cybersyn operation room. Based on participant observation, the essay argues that the interaction between visitors and the re-creation in such a particular moment is an invitation to reflect on how technology, socialism, and democracy sought to reinforce each other during the Cold War. The Cybersyn project, one of the most globally recognizable pieces of technology designed in the Global South, still resonates five decades after its implementation (and further destruction by the military), prompting new questions in an era of artificial intelligence and new threats to democracy.

The invisibility of the cognitive cost of military police work.

OBJECTIVE: To assess the cognitive cost of work for military police officers in the state of Rio de Janeiro. METHOD: This is a cross-sectional study with a quantitative approach, carried out with 446 military police officers, of both sexes, distributed between non-commissioned officers and officers, in the 7th, 15th, 20th, 24th and 41st Military Police Battalions. An instrument was used to depict sociodemographic, work, lifestyle and health conditions and a scale for assessing the human cost of work, which analyses the demands of the job through physical, cognitive and affective costs. The data was organized, processed and analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 13.1. RESULTS: The cognitive cost had the highest means, with severe results (µ = 3.86; SD = 0.86), representing greater demands in relation to the human cost of work among military police officers in the state of Rio de Janeiro and significant associations in relation to obesity, cognitive alterations in attention and memory, age and hours of sleep. CONCLUSION: In assessing the human cost of work, the cognitive cost was the most demanding in the work context of the military police officers surveyed, presenting a serious risk of illness.

Impact of childhood traumatic brain injury on fitness for service class, length of service period, and cognitive performance during military service in Finland from 1998 to 2018: A retrospective register-based nationwide cohort study.

INTRODUCTION: Traumatic brain injury (TBI) can cause neuronal damage and cerebrovascular dysfunction, leading to acute brain dysfunction and considerable physical and mental impairment long after initial injury. Our goal was to assess the impact of pediatric TBI (pTBI) on military service, completed by 65-70% of men in Finland. METHODS: We conducted a retrospective register-based nationwide cohort study. All patients aged 0 to 17 years at the time of TBI, between 1998 and 2018, were included. Operatively and conservatively treated patients with pTBI were analyzed separately. The reference group was comprised of individuals with upper and lower extremity fractures. Information on length of service time, service completion, fitness for service class, and cognitive performance in a basic cognitive test (b-test) was gathered from the Finnish Military Records for both groups. Linear and logistic regression with 95% CI were used in comparisons. RESULTS: Our study group comprised 12 281 patients with pTBI and 20 338 reference group patients who participated in conscription. A total of 8 507 (66.5%) men in the pTBI group and 14 953 (71.2%) men in the reference group completed military service during the follow-up period. Men in the reference group were more likely to complete military service (OR 1.26, CI 1.18-1.34). A total of 31 (23.3%) men with operatively treated pTBI completed the military service. Men with conservatively treated pTBI had a much higher service rate (OR 7.20, CI 4.73-11.1). In the pTBI group, men (OR 1.26, CI 1.18-1.34) and women (OR 2.05, CI 1.27-3.36) were more likely to interrupt military service than the reference group. The PTBI group scored 0.15 points (CI 0.10-0.20) less than the reference group in cognitive b-test. CONCLUSIONS: PTBI groups had slightly shorter military service periods and higher interruption rate than our reference-group. There were only minor differences between groups in cognitive b-test.

Occupational health screening during Gurkha Central Selection: a retrospective cohort study.

OBJECTIVE: The selection process to the British Army's Brigade of Gurkhas is rigorous, demanding and competitive. The ethos of recruitment to the Gurkhas is grounded in an overarching tenant: that selection is free, fair and transparent. The aim of this study was to retrospectively review reasons for potential recruits (PRs) to be deemed medically unsuitable or deferred suitability on medical grounds for selection to the Brigade of Gurkhas. METHODS: A retrospective review was conducted by extracted data from published post-exercise reports for the past four years to ascertain numbers of PRs deemed medically fit, medically unsuitable or deferred suitability on medical grounds. The International Classification of Disease version 11 (ICD-11) codes were retrospectively assigned to code medical reasons for non-progression. Rates of medical non-progression were compared by year. RESULTS: A total of 3154 PRs were analysed between 2018 and 2021. There was no significant difference between PRs deemed medically fit and those deemed medically suitable or deferred on medical grounds over the study period (p=0.351). There was a significant difference in the ratio of PRs deferred on medical grounds and those deemed medically unsuitable over the study period (p<0.05). CONCLUSION: Selection to the Gurkhas is extremely competitive. These data demonstrate that, overall, reasons for medical deferral or unsuitability have remained constant despite the impact of a global pandemic. These data reinforce the central tenant of Gurkha selection; that it continues to be free, fair, and transparent.

Exertional hyponatremia among active component members of the U.S. Armed Forces, 2008-2023.

Exertional hyponatremia, or exercise-associated hyponatremia, occurs within 24 hours after physical activity due to a serum, plasma, or blood sodium concentration (Na+) below the normal reference range of 135 mEq/L. If not detected early and managed properly, hyponatremia can be fatal. From 2008 to 2023, 1,812 cases of exertional hyponatremia were diagnosed among U.S. active component service members (ACSMs), with an overall incidence rate of 8.3 cases per 100,000 person-years (p-yrs). In 2023 there were 153 cases of exertional hyponatremia diagnosed among ACSMs, resulting in a crude incidence rate of 11.7 per 100,000 p-yrs. Female service members, those older than 40, non-Hispanic Black service members, Marine Corps members, recruits, those in combat-specific occupations, and ACSMs stationed in the Northeast U.S. region had higher incidence rates of exertional hyponatremia diagnoses than their respective counterparts. During the surveillance period, annual rates of incident exertional hyponatremia diagnoses peaked in 2010 (12.8 per 100,000 p-yrs) and then decreased to a low of 5.3 cases per 100,000 p-yrs in 2013. Thereafter the incidence rate fluctuated but has increased from 6.2 per 100,000 p-yrs in 2017 to its second-highest level in 2023. Service members and their supervisors should be aware of the dangers of excessive fluid consumption and prescribed limits for consumption during prolonged physical activity including field training exercises, personal fitness training, or recreational activities, particularly in hot, humid weather.

Heat exhaustion and heat stroke among active component members of the U.S. Armed Forces, 2019-2023.

The most serious types of heat illnesses, heat exhaustion and heat stroke, are occupational hazards associated with many of the military's training and operational environments. These illnesses can typically be prevented by appropriate situational awareness, risk management strategies, along with effective countermeasures. In 2023, the crude incidence of heat stroke and heat exhaustion were 31.7 and 172.7 cases per 100,000 person-years, respectively. The rates of incident heat stroke declined during the 2019 to 2023 surveillance period, but rates of incident heat exhaustion increased over the same period. In 2023, higher rates of heat stroke were observed among male service members compared to their female counterparts, and female service members experienced higher rates of heat exhaustion compared to male personnel. Heat illness rates were also higher among those younger than age 20, Marine Corps and Army service members, non-Hispanic Black service members, and recruits. Leaders, training cadres, and supporting medical and safety personnel must inform their subordinate and supported service members of heat illness risks, preventive measures, early signs and symptoms of illness, and appropriate interventions.

Exertional rhabdomyolysis among active component members of the U.S. Armed Forces, 2019-2023.

A largely preventable condition, exertional rhabdomyolysis persists as an occupational hazard of military training and operations, especially in high heat environments among individuals exerting themselves to their physical endurance limits. During the 5-year surveillance period of this study, unadjusted incidence rates of exertional rhabdomyolysis per 100,000 person-years among U.S. active component service members fluctuated, reaching a low of 38.0 cases in 2020 and peaking at 40.5 cases in 2023. The rate in 2020 constituted a decline of 3.8% from the rate in 2019 (39.5 cases). Beginning in 2020, incidence rates per 100,000 person-years gradually increased, by 1.8% in 2021 (38.7 cases), 5.3% in 2022 (40.0 cases), and 6.6% in 2023 (40.5 cases). Consistent with prior reports, subgroup-specific crude rates in 2023 were highest among men, those less than 20 years old, non-Hispanic Black service members, Marine Corps or Army members, and those in combat-specific and 'other' occupations. Recruits experienced the highest rates of exertional rhabdomyolysis during each year, with incidence rates 6 to 10 times greater than all other service members.