Objective.—Little is known about health care provider interest, knowledge, and beliefs regarding the health effects of human-induced environmental degradation (HIED). A survey was created and distributed to better characterize health provider beliefs about the adverse health effects of HIED.

Methods.—An invitation to participate in an online 24-question survey was e-mailed to 2177 members of the Wilderness Medical Society to characterize experience with health effects of HIED, types of health effects attributed to HIED, attitudes toward HIED, and educational sources about HIED. Data were analyzed from 665 responses, a response rate of 35%.

Results.—Results demonstrate that health care providers identify a large number and variety of health effects associated with HIED, although exacerbation of asthma, reactive airways disease, and chronic obstructive pulmonary disease were most commonly identified. Over 80% report that HIED has affected the health of a patient they have cared for; 60% report patients have asked about HIED effects on health; and 93% report that they do not distribute information to patients about HIED. Over 75% of respondents believe there is an unfulfilled need for information and education about the adverse health effects of HIED. Respondents report continuing medical education, journal articles, and medical schools/residency programs as the best methods for education and for raising awareness of the health effects of HIED.

Conclusions.—Results indicate strong health professional belief in health effects of HIED, patient concern related to the health effects of HIED, and a need to educate both health care providers and patients on the adverse health effects of HIED.

Objective.—The effect hydration status has on exposure to hypoxia is unclear. The purpose of the study was to identify how hydration status, above and below euhydrated levels, affects the physiological responses and onset of acute mountain sickness symptoms during acute normobaric hypoxia.

Methods.—Eight males completed intermittent walking tests under normobaric hypoxic conditions (FIo₂ = 0.13) after controlled hyperhydration, hypohydration, and euhydration protocols. A range of physiological, psychological, and altitude illness markers were monitored throughout the 125-minute exposure.

Results.—Heart rate, core temperature, peripheral arterial oxygen saturation, urine osmolality, and mean self-reported Lake Louise Questionnaire acute mountain sickness scores were significantly different between euhydration, hypohydration, and hyperhydration, respectively, and closely correlated with environmental symptoms questionnaire, Lake Louise questionnaire, and headache scores (P < .05). Other measures of ventilation and lung function were also significantly different between hydration conditions (P < .05).

Conclusions.—Hydration state above and below euhydration has detrimental consequences on physiological strain and onset of acute mountain sickness symptoms when exposed to acute normobaric hypoxia.

Objective.—To measure the incidence of acute mountain sickness (AMS) in adolescents travelling to moderately high altitudes.

Methods.—The study was carried out on a cohort of 63 adolescents with an average age of 15.9 years during an 8-day trip to Morocco, travelling to altitudes between 3106 m and 4167 m. The incidence of AMS was calculated using the Lake Louise questionnaire, which was completed twice daily by each participant. An episode of AMS was defined as being a score of 3 or more on the Lake Louise questionnaire in the presence of a headache. Difference in incidence between boys and girls was analyzed using 2-tailed Mann-Whitney U testing.

Results.—The daily incidence of AMS among 52 participants with complete data was found to be between 3.8% and 42.3% and increased with increasing altitude. Girls had a statistically significant higher incidence of AMS (80%) compared with boys (55%) (P < .01).

Conclusions.—Acute mountain sickness may occur more commonly in female adolescents than in male adolescents. Overall, however, it appears that the incidence of AMS in adolescents is similar to that found in adults in previous studies.

Objective.—Accurate reports of energy expenditure (EE) during prolonged mountaineering activity are sparse. The purpose of this study was to estimate EE during a winter ultraendurance climbing race and individual mountaineering activities in Mont Blanc, France.

Methods.—Seven days before the race, resting metabolic rate (RMR) and maximal oxygen consumption (Vo_2max) were measured in 10 experienced male climbers (30.0 ± 0.9 years). Three days before (reference period) and during the race, heart rate (HR) was recorded for estimation of total daily EE (TDEE), and the type and duration of all activities were collected through questionnaires. Total DEE was calculated by adding DEE during sleep (DEE sleep), sedentary (DEE sedentary), and during exercise (DEE exercise). Daily energy expenditure during exercise was determined through assumption of the rectilinear relationship between heart rate (HR) and Vo₂. Anthropometric measurements were performed 7 days before, just before, and immediately after the race.

Results.—Total time of the race averaged approximately 29 hours and 29 minutes, including 11 hours and 24 minutes in the hut, plus 18 hours and 5 minutes dedicated to climbing. During the race, TDEE was 43.6 ± 1.2 MJ·d⁻¹. Energy expenditures for cross-country skiing and alpine climbing were similar (57.3 ± 2.1 kJ·min⁻¹ and 54.0 ± 2.9 kJ·min⁻¹, respectively). An energy deficit of 33.5 ± 2.3 MJ resulted after the race, with a mean weight loss of 1.52 ± 0.31 kg (P < .001).

Conclusions.—Experienced climbers expended a high level of energy during a winter ultraendurance alpine climbing race at moderate altitude under high degrees of difficulty and risk exposure. These results provide comparative data on the energy cost of the main mountaineering activities during a race: cross-country skiing and alpine climbing.

Objective.—To explore the use of helmets in skiers and snowboarders injured at ski runs and terrain parks in Colorado and the northeast United States and to examine differences in head injury severity in terrain parks as compared to ski runs.

Methods.—This was a retrospective cohort study. We reviewed emergency department medical records of injured skiers at 9 medical facilities in Colorado, New York, and Vermont to examine the frequency of helmet use, type of terrain on which injuries occurred, and effect of injury event type and helmet use on change in mental status. Injuries that occurred from July 2002 to July 2004 were included. Eligible patients were skiers and snowboarders who sustained a head injury as defined by International Classification of Diseases-9 codes for acute head injuries. Data elements included event location, mechanism of injury, helmet use, loss of consciousness, neurologic findings, Glasgow Coma Scale score, and initial outcome. Data were entered into SPSS for analysis.

Results.—Of 1013 patients, 52.6% were skiing, 46.7% were snowboarding, and the remainder engaged in other activities such as sledding or using a sit ski. Most (78.7%) were using a ski run, whereas 19.1% were at a terrain park when their injuries occurred, and 37.1% were wearing helmets. Most injuries (74.1%) occurred when the victim hit his/her head on the snow; 10.0% and 13.1% occurred in collisions with other skiers and fixed objects, respectively. There were significantly fewer instances of loss of consciousness in fall events in the Colorado group (χ²: 4.127; P < .05), a significantly lower incidence of loss of consciousness in helmet users who struck a fixed object (χ²: 5.800; P < .05), and a significantly higher incidence of skiers colliding with fixed objects in the Northeast (χ²: 14.05; P < .005). There were significantly more documented head injuries in terrain parks, even when controlling for helmet use (χ²: 5.800; P < .05).

Conclusion.—There is an increased risk of head injury, regardless of helmet use, at terrain parks as compared to ski runs, and helmets were notably protective in collisions with fixed objects. Regional differences in injury events were noted in that there were more fall-related head injuries and a higher incidence of collisions with fixed objects in the Northeast compared to Colorado.

Objective.—Considering the adverse effects of exercise-induced cortisol secretion on health in athletes, it is important to determine the environmental and individual factors that contribute to the variations in exercise-induced cortisol secretion. In this study, the effects of cold environment exposure and cold acclimatization on exercise-induced salivary cortisol responses were investigated.

Methods.—Short track skaters (n  =  11), who usually practice under cold conditions, and inline skaters (n  =  11), who usually practice under room temperature conditions, participated in a randomized crossover study. All participants cycled for 60 minutes at 65% V˙o₂ max under cold (ambient temperature: 5 ± 1°C, relative humidity 41% ± 9%) and room temperature (ambient temperature: 21 ± 1°C, relative humidity 35% ± 5%) conditions. The participants had a 120-minute bed rest recovery phase at room temperature after both exercise bouts. Cortisol levels were measured in saliva samples collected pre-exercise and postexercise at 1 minute, 30 minutes, 60 minutes, and 120 minutes.

Results.—Both short track and inline skaters exhibited clear cortisol responses to exercise under cold and room temperature conditions. The magnitude of the cortisol response, however, was different between skaters and conditions. The inline skaters exhibited significantly higher cortisol values under cold conditions than under room temperature conditions (7.6 nmol/L and 4.2 nmol/L, respectively). However, the short track skaters exhibited significantly higher cortisol values under cold conditions compared to room temperature conditions (8.7 nmol/L and 5.4 nmol/L, respectively).

Conclusions.—The effects of cold environment exposure on exercise-induced cortisol response were different between skaters who usually practice under cold or room temperature conditions. These results can be interpreted as acclimatization to either cold or room temperature conditions attenuating the cortisol response, suggesting that acclimatization may be beneficial in reducing the exercise-induced cortisol response.

Objective.—To identify search and rescue (SAR) trends in US National Park Service (NPS) units.

Methods.—A retrospective review of the US National Park Service Annual Search and Rescue Reports from 1992 to 2007 and the SAR statistics for all NPS units in 2005.

Results.—From 1992 to 2007 there were 78 488 individuals involved in 65 439 SAR incidents. These incidents ended with 2659 fatalities, 24 288 ill or injured individuals, and 13 212 saves. On average there were 11.2 SAR incidents each day at an average cost of $895 per operation. Total SAR costs from 1992 to 2007 were $58 572 164. In 2005, 50% of the 2430 SAR operations occurred in just 5 NPS units. Grand Canyon National Park (307) and Gateway National Recreation Area (293) reported the most SAR operations. Yosemite National Park accounted for 25% of the total NPS SAR costs ($1.2 million); Wrangell-St. Elias National Park and Preserve ($29 310) and Denali National Park and Preserve ($18 345) had the highest average SAR costs. Hiking (48%) and boating (21%) were the most common activities requiring SAR assistance. Hiking (22.8%), suicides (12.1%), swimming (10.1%), and boating (10.1%) activities were the most common activities resulting in fatalities.

Conclusions.—Without the presence of NPS personnel responding to SAR incidents, 1 in 5 (20%) of those requesting SAR assistance would be a fatality. Future research and the development of any prevention efforts should focus on the 5 NPS units where 50% of all SAR incidents are occurring.

Objective.—To determine the prevalence and predictors of injury and illness among long-distance hikers.

Methods.—This was a cross-sectional study of long-distance hikers (>500 miles [805 km]) along the Appalachian Trail and Pacific Crest Trails between August and October of 2006. An 8-page survey instrument was made available to hikers at a designated station near the northern terminus of the respective trails. The survey questions were yes/no or multiple choice. Independent variables included packweight, footwear, and type and frequency of water purification. χ² tests to compare categorical data and the Cochran-Armitage test for trend were used (P < .05 significant). We used logistic regression to compare the variables concurrently, and significance was determined using likelihood ratio tests. Profile likelihood confidence intervals for the odds ratios are reported.

Results.—Of the 128 hikers completing surveys that met inclusion criteria, the mean age was 33 years (range  =  18–65 years), 94% walked >1500 miles (2400 km), and 70% were male. Using univariate analysis, trends were noted in the proportion of hikers reporting paresthesias and increasing packweight (35% with 10–20 pound [4.5–9 kg] packs, 50% with 21–30 pound [9.5–13.5 kg] packs, and 69% with >31 pound [14 kg] packs [P < .002]), as well as in the proportion of hikers reporting paresthesias and increasing footwear rigidity (29% sandals, 36% running shoes, 42% hiking shoes, and 68% hiking boots [P < .001]). In multivariate analysis compared to sandals, the odds ratio of suffering from paresthesias with running shoes was 1.57 (95% CI 0.3, 12.2), hiking shoes 1.73 (95% CI 0.3, 13.9), and hiking boots 3.9 (95% CI 0.7, 32.1) (P  =  .16). Compared to 10 to 20 pound (4.5–9 kg) packs, the odds ratios of suffering from paresthesias with 21 to 30 pound (9.5–13.5 kg) packs was 1.5 (95% CI 0.6, 3.9), and for >31 pounds (14 kg) was 2.2 (CI 0.7, 7.1) (P  =  .03). Adjusting for footwear and pack weight, only pack weight was significantly associated with paresthesias. Packweight and footwear were not significantly associated with other musculoskeletal injuries, such as joint sprains or chronic pain, and muscle injuries.

Conclusions.—There is an association between packweight and the prevalence of paresthesias among long-distance hikers. The association between type of footwear and the prevalence of paresthesias is significant when analyzed independently, but loses its significance when the variables are examined together. This suggests that there is confounding between footwear and packweight.

Objective.—To quantify awareness of acute mountain sickness (AMS) in a sample of visitors to a North American ski resort and to identify strategies and interest for increasing knowledge of AMS in that population.

Methods.—One hundred and thirty visitors to Big Sky Ski Resort, Montana, were surveyed. Demographic data were obtained. Respondents were asked about their current knowledge of AMS and then answered questions designed to quantify their depth of knowledge of the subject. Correct answers were correlated with demographic data. Respondents also answered questions indicating their interest in further education about altitude illness and their preferred modality for obtaining this information.

Results.—In general, most respondents were young, 18 to 30 years (62.3%), and male (62.5%). Seventy-six percent had at least some college education and more than 5 years of skiing/snowboarding experience. Only 55% of respondents had some knowledge of AMS, but only 30% had knowledge of AMS symptoms using the Lake Louise Scoring System. About 30% knew the lowest altitude this illness can occur. There was a correlation between educational background and improved knowledge of altitude illness. Half of the respondents desired further information about AMS, and the Internet was the preferred source of information.

Conclusions.—This study suggests that a large population of skiers in North America may be relatively naive to the dangers of AMS. The majority of the respondents were interested in learning more about altitude illness, and the Internet was the most attractive source of information.

Objective.—To assess a typical commercial trekking cohort for cognitive impairment after gradual ascent to 5100 m.

Methods.—We performed a prospective, controlled, repeated-measures study within a trekking expedition to Nepal. A sample of expedition participants was studied; 36 were enrolled and 26 completed all testing. Additional normative data were sourced from sea level studies. Participants underwent cognitive assessment before travel with written, verbal, and computerized tests, then within 24 hours of arrival at 5100 m after an 18-day ascent from 400 m. Changes in performance in 6 written and 7 computerized tests were analyzed at an individual and group level using paired t tests. Effect size analysis was performed for individual performance.

Results.—No individual demonstrated significant cognitive impairment at 5100 m. The subject group performed significantly better than the normative population in 3 of the 6 written tests. The group performed worse at 5100 m in 1 written test (digit span forwards, P < .01) and better in 2 written (digit-symbol substitution, P < .01; trail-making test, part B, P < .05) and 1 computerized test (monitoring test reaction time, P < .01). Performance was more variable in the written than the computerized tests.

Conclusions.—Gradual ascent to high altitude causes no significant cognitive impairment in the majority of individuals. Computerized testing produced less variable results than written testing, but logistical difficulties are likely to preclude widespread use of such technology in the field.

Objective.—Risk assessment is an important part of safe backcountry travel in avalanche terrain. The purpose of this study was to determine and compare the ability of backcountry travelers to accurately estimate the avalanche danger for their destination and time of travel.

Methods.—We surveyed 353 winter backcountry users, asking them to rate the avalanche danger for their destination that day. We then compared this estimation to the Utah Avalanche Center daily advisory for that specific location, aspect, and elevation. Tendency to underestimate the avalanche danger was then compared across 6 different sports (backcountry skiing, backcountry snowboarding, snowshoeing, snowmobiling, out-of-bounds skiing, and out-of-bounds snowboarding) as well as across age, gender, and subject participation in an avalanche safety course.

Results.—A comparison across different sports, adjusted for age and gender, showed that snowshoers were 7.11 times more likely than skiers to underestimate the avalanche danger (95% CI, 2.95, 17.11). This difference was maintained after adjusting for past education in an avalanche safety course (odds ratio, 5.74; 95% CI, 2.28, 14.46). Snowmobilers were also significantly more likely to underestimate the avalanche danger when compared to skiers (odds ratio, 3.11; 95% CI, 1.12, 8.24), but these differences ceased to be significant when the data were adjusted for avalanche safety course (odds ratio, 2.39; 95% CI, 0.84, 6.74). While there was a trend for women and older age groups to underestimate the avalanche danger when compared to men, these trends were not significant.

Conclusions.—Snowshoers and snowmobilers are groups that tend to underestimate avalanche danger when traveling in the backcountry. These groups may be unknowingly assuming a higher risk and should be targeted for avalanche education and awareness.

Considerable attention has been given to the shortage of anti snake venom in Africa. The current supply is reported to rest at crisis levels, and considerable attention has been given to reporting the crisis. What has been absent is a recommended list of anti snake venoms that suppliers can produce in order to alleviate the problem. Suppliers who may want to enter the market and provide new anti snake venoms are hampered by a lack of knowledge of which to provide, where to source the venoms necessary for production, and the likely volume levels required. Snakebite epidemiology is recognized as being poor, particularly in estimating the number of envenomations. Snakebite authorities and organizations such as the World Health Organisation have provided lists of medically significant species, but these are inadequate as a guide to production. This paper proposes a list of anti snake venoms that could be produced by suppliers and crucially lists relevant species by geographical area, venom sources for the target species, and likely production volumes to enable suppliers to develop a confident forecast of demand to ensure sustainability.

Objective.—Mountaineers face a variety of health risks at altitude including pulmonary edema; portable ultrasound may be used to diagnose high altitude pulmonary edema. This report tests the functionality of electronic equipment in a hypobaric test environment and the ability of remotely guided nonexperts to use ultrasound to evaluate respiratory status on Mt Everest.

Methods.—Two ultrasound devices and associated video equipment were tested in a cooled (4°C–5°C) hypobaric chamber to 27 000 feet (8230 m) before travel to Mt Everest. The ultrasound system was connected via satellite phone to a video streaming device and portable computer to stream video through the Internet for remote guidance of a novice user by an expert. Pulmonary interstitial fluid was quantified by the presence of “comet tail” artifacts.

Results.—There was no notable degradation in equipment performance in cold, hypobaric conditions; ultrasound confirmation of increased comet tails was noted in the chamber despite oxygen supplementation and the very brief exposure. Two pulmonary surveys of asymptomatic participants were completed by novice operators within 25 minutes on Mt Everest. The remote expert was able to guide and identify comet tails suggestive of intermediate pulmonary interstitial fluid. Image quality was excellent.

Conclusions.—The tested ultrasound devices functioned nominally in cold, hypobaric conditions; acute changes in lung fluid content were noted in these conditions despite normoxia. We successfully used a satellite telemedical connection with a remote expert to guide thoracic ultrasound examinations at Advanced Base Camp on Mt Everest. Coupling portable ultrasound with remote expert guidance telemedicine provides a robust diagnostic capability in austere locations.

Rabies is a preventable, fatal infectious disease. Successful vaccination programs for domestic animals in developed countries have drastically decreased the risk of exposure to rabies. Yet awareness of rabies needs to remain high as important reservoirs still exist in our backyards, the wilderness, and abroad. Recognizing the risk before and after a potential exposure, so that appropriate medical care can be sought, is critical to preventing a fatal complication. This case report involves an exposure of a medical student to an ill-appearing and likely rabid gray fox in the Gila Wilderness Area of New Mexico. The student was a member of a 28-day wilderness medicine course taught by the National Outdoor Leadership School/Wilderness Medicine Institute in collaboration with the Harvard Affiliated Emergency Medicine Residency. On the first night in the field, the student awoke to a gray fox biting his foot through his sleeping bag in the early morning hours. Subsequently the student was evacuated for medical evaluation. Further care consisted of rabies postexposure prophylaxis, including thorough wound cleansing, injection of human rabies immunoglobulin, and initiation of a rabies vaccination schedule. Immediate wound care with soap and water and a viricidal agent is of utmost importance for any animal bite, but especially so in the prevention of rabies. Indications for rabies prophylaxis are complex and require prompt evaluation by a medical professional and consultation with local epidemiology to guide treatment.