Wilderness & Environmental Medicine

In extreme cold weather (ECW) environments it may be beneficial to activate an auto-injector through clothing rather than against skin to minimize casualty exposure. It has been shown that popular adrenaline auto-injectors may not deliver an adequate intramuscular dose to individuals with increased subcutaneous fat, even when activated against skin. This experiment sought to build on research into auto-injector use in the ECW environment by assessing drug delivery through winter clothing combinations with varying simulated skin-to-muscle distances (STMD).

Investigators based at the British Antarctic Survey Medical Unit (BASMU) in Plymouth, UK, tested two brands of auto-injector, EpiPen and Emerade, through commonly worn clothing sourced from the British Antarctic Survey. The experiment involved activating the auto-injector through clothing layers and different depths of silicone representing subcutaneous tissue. The volume administered through these layers was collected and its mass was measured. This mass was taken as a representation of the drug volume delivered through the various clothing layers, subcutaneous tissue, and muscle.

The EpiPen administered adrenaline through all clothing combinations tested at STMD 5 mm; however, thicker clothing combinations at STMD 10 mm prevented effective drug delivery. The Emerade auto-injectors delivered adrenaline at an acceptable dose through the thicker combinations at STMD of 10 mm and 15 mm.

These results suggest that adrenaline auto-injectors can successfully activate through polar clothing but that the depth of injection may be reduced. This may be more consequential in individuals with a greater STMD and should be considered when treating patients in cold environments.

Surfing is a popular activity that also plays a crucial role in aquatic safety because surfers can act as first responders in emergencies. The objective of this brief report was to assess the feasibility of a surf-specific functional workout integrating aquatic rescue activities and cardiopulmonary resuscitation (CPR) and to examine whether CPR quality is preserved under physiologic fatigue.

A descriptive pilot study was conducted with 10 surf instructors who received a CPR refresher session before engaging in a CrossFit-based workout of the day using an as-many-rounds-as-possible format. This included rescue, extraction, and resuscitation activities. Variables including repetition time, heart rate, perceived exertion, and CPR quality were analyzed.

Surfers maintained consistent rescue times, especially in the first 2 repetitions, with an average heart rate at 83% of their maximum and a perceived exertion of 8. CPR quality remained high, with a median CPR quality score of 89% initially and 91% in the second repetition. No significant differences were found in CPR quality between rounds.

This pilot study showed that a surf-specific functional workout may be used as a physiologic simulation of rescue-to-resuscitation transitions, during which CPR quality can be preserved despite high perceived fatigue. These findings support the feasibility of this approach for simulating operational demands rather than demonstrating training efficacy.

Podcasts are a popular medical education tool, especially for the review of journal articles, but production requires significant resources. The objectives of this study were to determine the feasibility of a trained artificial intelligence (AI) model generating well-received educational podcasts based on journal articles and to assess listener comprehension with knowledge-based questions.

Google Gemini 2.0 Flash AI was trained on 12 Wilderness and Environmental Medicine journal articles to generate 3 distinct educational podcasts (4 articles per podcast). These podcasts featured 2 AI-generated host voices in a journal club format. Participants from the Wilderness Medical Society Student/Resident Committee, the Virginia Tech Carilion Wilderness Medicine Fellowship Program, and a convenience sample of students and residents were randomly assigned to listen to 1 podcast, blinded to its AI origin. They then completed a 5-point Likert perception survey and a knowledge assessment with continuing medical education-style multiple-choice questions based on the discussed articles.

Thirty-one participants completed the study. Participant perception was highly positive: 87.5% agreed or strongly agreed that the content was accurate and relevant (mean Likert score 4.37), and 81.25% agreed or strongly agreed that the podcasts aided journal article review and learning (mean Likert score 4.14). The mean knowledge assessment score was 88.7% correct (SD 5.0%).

Despite limitations, including a small sample size and lack of a control group, AI-generated podcasts were positively received and effectively conveyed educational content, as evidenced by high knowledge assessment scores.

Actively recreating in natural environments enhances physical and mental health but also carries risk. We aimed to characterize wilderness day hikers and trail runners and examine factors that predict preparedness.

We conducted a cross-sectional survey in 4 distinct areas of Rocky Mountain National Park in Colorado during June to August of 2024. English-speaking adults returning from a day hike or trail run were invited to participate. We classified visitors as prepared based on the gear they reported carrying.

Of 801 potential participants approached, 586 day hikers (82.3%) and 68 trail runners (76.4%) agreed to participate. The overall average age was 40.7 y (range 18–82 y), 50.1% were female, and the most common state of residence was Colorado (47.3%). Day hikers tended to be older, travel in larger groups, and spend fewer days in the wilderness per year, whereas trail runners reported higher levels of experience and wilderness preparedness and were more likely to experience “close calls.” A minority of participants met our definition of wilderness prepared, about half were altitude prepared, and approximately a quarter did not tell anyone where they were going or when they expected to return. Several measures of experience were associated with preparedness.

Both equipment and knowledge are important for safely when enjoying and leaving wilderness settings. Yet, many wilderness users in Rocky Mountain National Park did not meet our definition of adequate preparation, especially those with less experience. Additional efforts to increase the proportion of wilderness day users who are prepared may help further improve visitor safety.

Carbon monoxide (CO) poisoning is a public health concern. Devices relying on internal combustion represent a common source of contamination. The colorless and odorless nature of the gas reinforces the importance of active monitoring. Intoxication may be missed, with the potential of life-threatening compromise. The impact may be accentuated at high altitude, where lower barometric pressure reduces oxygen availability. CO hazards are a known and likely underreported issue in remote high altitude facilities. We evaluated CO levels produced by internal combustion sources in various field camp environments.

CO levels in kitchens, dining areas, shower spaces, cooking tents, and seasonal ice-fishing tents were opportunistically measured using portable CO detectors (Reed Instruments R9400). Normally distributed data are reported as mean±SD or, with small samples, as range values.

Measurements were taken in Nepal (n=24; altitude 3606±520 m), Argentina (n=3; altitude 3240–4950 m), and Canada (n=3; altitude 198 m). The highest CO levels were found in shower spaces. Half the shower measures (7 of 13) exceeded World Health Organization recommendations for a 15-min CO exposure (86 ppm), with a peak measure of 1036 ppm.

Our sample size was small, but CO levels were seen to vary widely across field facilities, peaking in enclosed shower spaces, where World Health Organization recommendations were frequently exceeded. Elevated levels may pose safety risks, highlighting the need for better monitoring and public education.

Musculoskeletal injuries from rock climbing are increasing as participation rates rise. It is important to understand climbers’ injury treatment decisions and trust in providers to improve communication, education, and care pathways. The purpose of this study was to examine healthcare-seeking behaviors and healthcare-provider trust among rock climbers following injury.

A cross-sectional survey was distributed online via social media, email, and flyers. In total, 145 rock climbers who sustained a climbing-related musculoskeletal injury completed the survey. Outcomes included type of provider seen, reasons for provider choice or delay in care, and ratings of trust and satisfaction. Free-text comments were analyzed for themes.

Climbers commonly sought care from physical or occupational therapists (PT/OTs; 31.7%), followed by specialists (24.1%) and primary care providers (PCPs; 16.6%, P<0.001). PT/OTs were more likely to be accessed virtually and through peer recommendation, whereas PCP visits often were assigned by the health system. Delays in care were common (68.3%) and attributed to cost, time constraints, and confidence in self-treatment. Pulley injuries were associated with delayed care and reliance on self-treatment. Trust/satisfaction ratings were highest for PT/OTs (median trust 9, satisfaction 9) and specialists (trust 9, satisfaction 8) compared with PCPs (trust 6, satisfaction 6; P=0.02 and P=0.002, respectively). Free-text responses emphasized the importance of climbing-specific expertise and individualized treatment plans.

Trust and satisfaction with healthcare providers vary based on sport-specific knowledge and treatment recommendations. Delayed care and self-management are common, especially for finger injuries. PT/OTs often serve as both initial and final providers.

Exposure to spaceflight and microgravity environments has been implicated in large reductions in astronaut bone mineral density (BMD). While low BMD is a known risk factor for fracture, there have been no reported cases of in-flight fracture, and very little documentation of post-flight fracture. The present study sought to review the incidence of fractures within 5 years of return to spaceflight.

Using NASA's Lifetime Surveillance of Astronaut Health epidemiology database, a retrospective cohort study was conducted to identify the incidence of fracture in the 5-year post-flight period. All astronauts who participated in spaceflight with 5-year post-flight medical data were included. Demographics were compared between the fracture and nonfracture cohorts.

Of the 242 astronauts who met the inclusion criteria, 7 (2.9%) sustained fractures within 5 years post-flight. Three post-flight fractures occurred in the hip or spine. Six of the 7 fractures occurred within 2 years of return from spaceflight. Spaceflight length, age, and time from spaceflight were not statistically significantly associated with increased risk of fracture.

Fracture upon return to the gravitational environment is a serious risk for astronauts that can significantly jeopardize astronaut health and mission success. Fractures of the hip and spine, specifically, are associated with decreased BMD. While the incidence of these fractures is roughly 1%, the negative implications, including high 1-year mortality rates and functional implications, emphasize the need to optimize bone health and fracture treatment protocols.

The use of electric mountain bikes (e-MTBs) has grown rapidly in recent years in the Alps. This study aimed to compare injuries and associated factors among e-MTB and traditional mountain bike (MTB) riders in bike parks and biking facilities in western Austria.

Data on injured e-MTB and traditional MTB riders were collected via bike patrols and regional rescue services using an online reporting tool. Information included sex, age, nationality, accident site, trail steepness, injury circumstances and causes, transportation mode, affected anatomic regions, and injury diagnoses.

A total of 316 injured mountain bikers were documented, of whom 79.7% were male. The mean age of the injured individuals was 29.8±14.3 y. Among the recorded cases, 35 individuals (11.1%) were using an e-MTB. Injured e-MTB riders were, on average, significantly older than traditional MTB riders (35 vs 30 ys). Significant differences were observed between injured e-MTB and traditional MTB riders with respect to accident locations, slope steepness, circumstances and causes of injury, and mode of transportation. Although the head was the most frequently injured region among e-MTB riders (21%), the clavicle/shoulder region was the most frequently injured area among traditional MTB riders (32%). The most frequent injury diagnosis in both groups was a fracture, but fractures affected ∼27% of e-MTB riders compared with 52% of traditional MTB riders.

This study highlights significant differences in demographics, injury patterns, and accident circumstances between e-MTB and traditional MTB riders who have been injured.

The purpose of this study was to investigate coagulatory changes across multiple wildfire seasons among wildland firefighters.

We evaluated data on 127 federal wildland firefighters. Pre- and post-season and pre- and post-shift wildland fire response measurements were obtained, including venous blood samples analyzed for platelet closure time; prothrombin time, partial thromboplastin time, and activated partial thromboplastin time; lipids (cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides); high-sensitivity C-reactive protein; and complete blood cell counts with differential (hemoglobin, hematocrit, red blood cells, white blood cells, lymphocytes, monocytes, neutrophils, basophils, and eosinophils).

Pre- to post-season, there were decreases in high-sensitivity C-reactive protein and prothrombin time; no change in partial thromboplastin time, platelet count, and platelet closure times; and increases in white blood cells, hemoglobin, and hematocrit. Changes over a shift showed that white blood cells, lymphocytes, monocytes, neutrophils, and high-sensitivity C-reactive protein increased and eosinophils and partial thromboplastin time decreased. Platelet number was unchanged, but platelet closure time was prolonged.

We found no evidence of increased coagulatory potential following a season of firefighting activity and only modest changes in white blood cells, suggesting that there may not be long-term increased thrombotic potential (formation of blood clots) with wildland firefighting. We found conflicting evidence of increased and decreased coagulatory potential following a single shift of wildland firefighting, although neither the procoagulatory nor anticoagulatory shifts were of great magnitude.

The impact of lower limb joint replacement on those wishing to return to climbing has not yet been studied. This study aims to assess self-reported return to climbing and any themes or commonalities leading to any reduction in their return to the sport.

An online questionnaire was widely disseminated to climbers and mountaineers across the United Kingdom. Responses were collected from those who had undergone either hip, knee, or hip and knee replacement. The participants’ age range, gender, site and number of joint replacements were recorded together with their current joint-specific and activity scores. Participants also were asked to score their climbing ability in the 3 months prior to surgery and then 3, 6, and 12 months after surgery.

Among participants, the median Oxford Hip Score (OHS) and Oxford Knee Score (OKS) after surgery ranged from 45.5 to 48 (OHS) and 36 to 48 (OKS). Median measurements of physical performance ranged from 4 to 8 (Tegner) and 7 to 10 (UCLA). The median climbing score fell from 9 (best prior to surgery) to 8 (3 months prior to surgery) (P<0.05). In the 3 months following surgery, the median climbing score fell further to 5 (P<0.05). Although this improved in subsequent months, it did not exceed that found before surgery.

Our research reveals that it is possible to climb again after lower limb joint replacement. Although some climbers return to their previous level of performance, many do not. Further research is needed to determine why this occurs and what interventions are available for those who wish to do so.