The Intersection of Geriatrics,Climate Change,and Wilderness Medicine: Education is Critical

Abstract

According to the US Census, for the first time in history, older adults are projected to exceed the number of children by 2035. These seniors are headed to the outdoors in increasing numbers and face unique risks. They benefit from careful pre-event evaluation planning to maintain their health in wilderness environments. Climate change is affecting all of us, but seniors are considered an especially vulnerable group. This vulnerability needs to be addressed not only when older adults head into the wilderness but also when the wilderness “comes to them” in areas where wilderness medicine and disaster medicine overlap. Education of both providers and patients is vital. This article aims to discuss the special needs of older adults/seniors /elders (defined as those over 65 unless otherwise indicated) in the wilderness as well as the vulnerability of older adults to climate change, both during planned wilderness activities and when the wilderness “comes to them” because of climate change, and to identify opportunities for education and adaptation of patients and education of physicians and wilderness and disaster responders to care for these older patients. The PubMed and Google Scholar Database search engines were utilized to review relevant English language publications between 2000 and 2023 that addressed individuals over 65 and explored the overlap of geriatrics (aged over 65), wilderness and disaster medicine, and climate change and create a perspective summary. Because of increased numbers of older adults heading into the wilderness for outdoor activities or having wilderness thrust upon them due to climate change, cross training of all specialties including the fields of emergency, geriatrics, wilderness medicine, and disaster medicine is needed in collaboration with other organizations and search and rescue. Response agencies must recognize that training in wilderness medicine provides a background for practitioners working in dangerous and remote settings and ought to seek out individuals with such skills when placing responders in the field. Climate change is making these intersections and the need for this education more urgent with time.

Seniors and Outdoor Risk

According to the recent US census, for the first time in history, older adults (over 65 years old) are projected to exceed the number of children by 2035. By 2060, the number of older Americans is expected to double, the 85-and-older population will triple, and the percentage of older adults of color will increase from 23% to 45%, placing increased demands on the US healthcare system.^1–3

Adults over 65 already have the highest emergency department (ED) use rates in the United States and worldwide. They often suffer from multiple comorbid diseases and have a high incidence of polypharmacy, mobility disorders, and cognitive impairment. Many of these older adults also have poor social support and utilize the ED as their primary source of health care delivery. ⁴ As climate change increasingly impacts these adults, ED visits will likely increase. Therefore, physicians need to “geriatricize” their clinical acumen. ⁵ Medical schools and specialty training programs have increased geriatrics teaching in the curriculums. Although there is now a geriatric emergency program, supported by both ED physicians and the American Geriatric Society, and an Institute for Healthcare Improvement (IHI) Age-Friendly Health System Initiative, participation has been scarce. ⁶

In 2020, 7.1 million new Americans participated in at least one outdoor activity. There were 3.8 million total more participants in 2022 than in 2021. Seniors age 65 and older were in the fastest growing age category with 16.9% growth since the COVID pandemic began in early 2020. ⁷ Many of these people were retirees seeking more vigorous outdoor recreational activities ⁸ or following nature prescriptions given as an adjunct to standard care. ⁹ While there are numerous reasons for this increased participation, several studies have associated emotional well-being and pandemic resilience.

In addition to these American participants, according to Darat, the World Tourism Organization anticipates that the number of international travelers seeking outdoor activities will approach nearly 2 billion by 2030, with an estimated 15–30% of travelers aged 60 years or older. This older traveler group tends to have at least one chronic noncommunicable disease, and treatment of these should be optimized in advance of both domestic and international wilderness travel. Senior's inability to adapt physiologically during journeys increases the risk of exacerbation of their chronic medical conditions and reduces their immune response to travel vaccines. Medication side effects and possible drug-drug interactions can also occur. ³ Even in patients without serious chronic conditions, significant physiologic changes occur with normal aging. Regular exercise can lessen these impacts but does not prevent these changes. Physiologic changes including decreased cardiac output, decrease in age-predicted maximal heart rate, decrease in VO2max (the maximum rate of oxygen the body can use during exercise), increased incidence of coronary artery disease, decreased muscle mass with loss of muscle power and endurance, decline in cognitive function, slower reaction times, increased risk of falls or injury, greater incidence of depression, and greater incidence of sensory (hearing and vision) impairment occur. ¹⁰

As a result of these conditions, older outdoor participants are significantly more likely to experience a trauma or be evacuated because of an illness or a ground-level fall. Men are more likely to sustain an injury because of their mobility issues or fall from height and are lost more frequently than women. Women have ground-level falls more often than men.^11–13 The relationship between age and need for search and rescue missions is directly proportional. The number of injuries is greater in the >50-y-old age group and is associated with the highest risk of death.^11,14 Platts-Mills suggests that “Between 1980 and 2010 there was an approximately fivefold increase in reports of older adults experiencing mountaineering accidents from Accidents in North American Mountaineering. These findings are important because age is a risk factor for adverse outcomes after trauma. This information has potential implications for prevention and rescue preparedness.” ¹⁵ Focusing on fatal accidents, several sources^12–14 agree that people over 40 and 50 years old are overrepresented. Also, the “over 50s” is the only age bracket for which the number of rescue interventions increases every year. ¹⁴ Those in their 60s and 70s were at most risk for needing a rescue. ¹⁴ Older rock climbers get a higher proportion of overuse injuries, especially degenerative conditions, than younger athletes. Although the injury distribution overall is comparable, degenerative conditions, such as impingement syndrome of the shoulder or osteoarthritis of the fingers, are common injuries in older athletes. ¹⁶ Trauma and cardiovascular events are the largest mortality risks to older extreme travelers.^14,17,18 Prolonged physically or emotionally stressful travel may unmask or aggravate cardiovascular disease. Additional language, cultural, and culinary changes further increase cardiovascular stress. Myocardial infarctions disproportionately occur (21%) within the first 2 days of travel. ¹⁷

Cold, heat, or altitude exposure can aggravate ischemic conditions even without exertion in patients with underlying cardiac disease. Cold stress increases mean arterial pressure, total peripheral resistance, cardiac workload, and myocardial oxygen requirements during both rest and exercise, increasing the risk for angina and other cardiac events. Cold water swimming can change or mask angina symptoms. Hot conditions vasodilate peripheral vessels and cause additional cardiovascular demands to aid in body cooling. Hot and dry conditions can lead to body water losses and further stress the diseased cardiovascular system. The risk of sudden cardiac death in hikers at altitude increases with age in an exponential fashion starting in the fourth decade. However, although altitude will increase the workload on the heart due to lower partial pressure of oxygen, altitude does not increase the risk of acute coronary syndrome above that at sea level for the same workload in stable coronary artery disease. ¹⁹

Differentiating risk levels and making participation recommendations for wilderness travel is an important component of medical clearance for patients with cardiac disease. This should include optimizing medical management of their cardiovascular or other medical conditions, entering a conditioning program well in advance of departure to build endurance for the activity, avoiding or quitting cigarette smoking and tobacco use, using caution when exercising in extremes of temperature (hot or cold), being familiar with their angina symptoms, and being aware that low-oxygen environments may provoke undetected ischemia or worsen usually stable congestive heart failure. ¹⁹

This preparticipation consult should also include patient education on medication use, effects of climate change on an individual patient's conditions, warning signs of worsening disease, and general tips to ensure safe participation in most wilderness pursuits. ¹⁹ Most injuries and rescues occur from underestimating the risks of extrinsic, environmental factors and/or overestimating the patient's intrinsic skills. Therefore, extrinsic and intrinsic factors faced by the patient should be corrected by matching the patient's fitness and skill level to the environment to reduce the risk of serious injury. ²⁰ Those extrinsic environmental demands that can potentially affect the patient during their outdoor pursuits include temperature, terrain, altitude, weather, infection risk, dangerous wildlife, or plants; demands in terms of metabolic equivalents (METS); and available resources/evacuation options. ¹⁹ As discussed later, climate change has a large impact on all these areas. Intrinsic factors encompass wilderness experience, age, fitness, local knowledge, psychologic state, skill level, previous injuries, underlying medical issues, vaccine status, medications, and composition of the group. ¹⁹ Group composition is important since the experience and combined intrinsic and extrinsic factors of all the group members form a separate risk factor. The group is only as strong as the weakest member. The limitations of the leader and individuals within the group and of the overall group can have a large effect on the success and safety of the trip. ²⁰

Evaluation of wilderness adventure participants has been covered by Cushing, ¹⁹ Erb, ⁸ and Grissom.^21,22 Older travelers who are at increased cardiovascular risk need assessment before travel because prolonged physically or emotionally stressful travel may unmask or aggravate cardiovascular disease. Boulware even suggests that all persons over 50 years of age with any cardiovascular risk factors should also carry a copy of their baseline EKG. ¹⁷ Some authors suggest that the simplest method of assessing exercise capacity and planned exercise intensity is to use metabolic equivalents (METS) and adjust trip planning accordingly. ¹⁹

Recently, more older patients with medical conditions are seeking medical advice for high-altitude adventure travel. In these cases, physicians must consider how decreases in barometric pressure and pulse oximetry affect the underlying condition during the high-altitude trip. METS calculations are usually estimated at sea level. If the patient is doing similar activities at altitude, the energy expenditures can increase dramatically. ¹⁹ Assessment by a specialist with training and personal experience in high-altitude medicine may be needed as they can recommend individually adjusted programs, especially concerning adequate time for acclimatization. ²³

Luks and Hackett provide a thorough summary of physiologic responses of these patients based on absolute altitude reached, rate of ascent, sleeping elevation, and time and degree of exertion at that altitude. ²⁴ The authors recommend that pretrip evaluation addresses four main questions: whether the patient is at risk of severe hypoxemia or impaired oxygen delivery (lung and congenital heart disease), impaired ventilatory responses (chronic hypercarbia, neuromuscular disease, obesity hypoventilation syndrome, impaired carotid body function), abnormal pulmonary vascular responses to hypoxia (pulmonary hypertension, right heart failure), or complications due to underlying conditions (sickle cell, uncontrolled Coronary artery disease, vascular malformations). ²⁴ They suggest the best tool for risk stratification and training may be graded exposure to high altitude in safe settings, noting that certain conditions like asthma and congestive heart failure have symptoms that can fluctuate over time. The disease needs to be in good control, with planned directed medical therapy for exacerbations and plans if insulin pumps, glucose monitors, or inhalers malfunction in high altitude and cold. Dose adjustments for altitude illness must also be considered. ²⁴ Older age in itself is not associated with the development of acute mountain sickness. ²⁵ New Wilderness Medical Society (WMS) altitude guidelines are being written. For most wilderness activities, providers should recommend at least 6 weeks of training depending on the baseline level of fitness and wilderness experience, simulating as closely as possible the environmental conditions to be encountered. ²⁰

Climate Effects on Seniors

In addition to these issues, coinciding with senior demographic shift and more seniors doing wilderness pursuits, the rate of climate change is accelerating. Individuals ≥65 years of age are consistently identified as a population that is especially vulnerable to climate change stressors. ²⁶ Vulnerability is a function of exposure, sensitivity, and adaptive capacity. Those over 65 are affected on all these fronts. ²⁷ Normal aging creates less muscle and body tone; increased susceptibility to toxins, heat, cold, smoke, and disasters; increased complex medical conditions that impact abilities and responses; and increased dependence on intact medical delivery systems, medications, life-sustaining equipment, and transportation, which can be fragmented during climate disasters. They are also affected by social determinants of health like economic security or substandard housing, location in high-risk areas, social isolation, and reluctance to ask for help.

Adults over 65 are especially sensitive to extreme heat and other extreme weather events, degraded air quality, and increases in the risk of infectious diseases. Some of these impacts are projected to occur in places where older adults are heavily concentrated and likely to be most exposed. ²⁸ This confluence of sensitivity, exposure, and adaptive capacity determines older adults’ overall vulnerability to climate change. Older Americans have less capacity to adapt to these climate stressors.^28–31

In the past 20 years, there has been a 54% increase in heat-related mortality among persons older than 65 years of age, with more than one-third of all global warm-season, heat-related deaths attributable to climate change. ³² Several physiological changes from the aging process raise the predisposition of older people to heat-related circulatory collapse. Aging causes reductions in evaporative cooling efficiency due to decreased overall sweat production, exacerbated by the fact that elders are less able to redirect blood flow away from the deep splanchnic vasculature to the skin for cooling. Also, there is a reduction in surface thermoreceptor density in older adults. Aging is also associated with weaker contractile force of the heart in response to heat, making older hearts less capable of maintaining sufficient cardiac output in response to drops in blood pressure and left ventricular preload. Multiple analyses have demonstrated both advanced age and low socioeconomic status to be independent determinants of poor cardiovascular outcomes from air pollution, wildfires, heat waves, and natural disasters.^33,34,35 Many chronic diseases are exacerbated or triggered by exposure to heat, including ischemic heart disease, cardiac dysrhythmias, ischemic stroke, asthma and chronic obstructive pulmonary disease, respiratory tract infections, hyperglycemia, kidney failure, and neuropsychiatric disorders. ³²

Despite improved public messaging regarding heat-related health dangers, the number of deaths due to heat wave mortality remains high. Better education and increased awareness of the detrimental health effects of heat waves, especially in the elderly, may help reverse this trend, and policy actions are required to enhance the public health awareness regarding the deleterious effects of heat waves on human health.

Climate Change, Seniors, and Disasters

Climate change's causal connection to natural disasters can be expected to cause a rise in humanitarian crises. ³⁶ Clinically, it is already affecting emergency medicine practice through the amplification of climate-related disease patterns and epidemiologic shifts for conditions diagnosed and treated in emergency departments, especially for vulnerable populations like seniors. In addition, climate-driven intensification of extreme weather is disrupting health care delivery in EDs and health care systems overall. ⁴ One of the most imminent threats to emergency medicine operations is patient surges caused by acute and unprecedented climate events. ⁴

However, the emergency department is only one part of the healthcare chain. There is growing evidence to support networked geriatric care, especially in the face of climate change, through enhanced training in all specialties, including wilderness and disaster medicine.

The impact of a disaster is determined by the hazard itself, the vulnerability of the affected people, and the capacity or measures that can be taken to reduce or cope with the potential negative consequences. ³⁷ The frequency of international disasters has grown from fewer than 10 events per year in the mid-20th century to several hundred per year. ³⁷ Research conducted before, during, and after disasters can improve assessments of population health and health system vulnerabilities and capacities and help evaluate the effectiveness of integrated disaster risk management and adaptation strategies. ³⁸ The ability of a disaster victim to prepare for, respond to, and recover from a disaster depends on a variety of factors that often are beyond the individual's immediate control. ³⁹ In addition to health-related conditions, other factors may also contribute to these limitations as these persons may have no reserve to cope even with minimal stress. Many people over 65 years old report difficulties with two or more activities of daily living (ADL). Because these persons maintain the primary responsibility for caring for themselves, one of the greatest resources is self-preparation, and reminding them and their families of this responsibility is important. Education of patients, their families, and their communities about risks is key. ³⁹

About 80% of older adults have at least one chronic condition, and 50% have at least two chronic conditions that make them more vulnerable during a disaster. These chronic conditions combined with the physiological, sensory, and cognitive changes experienced as part of aging can result in frail older adults having special needs during emergencies. Planning and coordination among public health and emergency preparedness professionals and professionals who provide services for the aging are essential to meet these special needs. Several tools and strategies already exist to help prepare these professionals to protect and assist older adults during a disaster. ⁴⁰ Seniors Without Families Triage (SWIFT) has developed a screening tool for use in both pre- and postdisaster phases to assess the needs of the frail and to identify or triage those requiring care most rapidly. ⁴¹

The 2019 University of Michigan National Poll on Healthy Aging found that less than half of 50- to 80-year-old adults had taken steps recommended by disaster preparedness agencies. More than half stated they would find it difficult to afford to stay somewhere else for a week, were not confident that they were prepared to take care of themselves or a family member if a power outage lasted more than a day and were not prepared for an evacuation of the home or for a severe weather event. ⁴² After a disaster, conditions such as stress, the lack of food or water, extremes of heat or cold, and exposure to infection can contribute to the rapid worsening of a chronic illness that was under control before the event. Interruptions in medication regimens and needed medical technologies also can exacerbate underlying conditions and increase the risk of morbidity or mortality. Older adults with chronic conditions also may face health risks from either inadequate nutrition or from too much sodium, fat, and calories contained in the meals ready-to-ea (MRE) packages often offered to evacuees. Public health professionals can create the most effective disaster preparedness plans for vulnerable adults by working with the agencies responsible for services to the aged, including state and local departments on aging, local service providers, and Indian tribal organizations under the auspices of the Federal Older Americans Act. During a disaster, this network reaches out to its clients and identifies those who need assistance obtaining food, water, shelter, or medications. ⁴⁰ The CDC has published a planning guide that takes this system into account. ⁴³

Several recent government and international organization reports suggest that lack of attention to older people's needs in disaster response is worse in urban than rural areas. ⁴⁴ They also suggest that a preponderance of literature focuses on predisaster preparedness and long-term disaster recovery with a relative lack of attention to the response phase during disasters, especially in urban areas.^44–46 Although most research has focused on heat, hurricanes, and flooding, wildfire also has unique health impacts spreading beyond a specific boundary where the disaster occurred and needs to be addressed. ⁴⁷ Help Age International has published disaster and humanitarian crises guidelines for best practices in dealing with the elderly during disasters. These include checklists for communities and references to aid in further development of programs. ⁴⁸

Wilderness Medicine and Disasters

Disasters in resource-poor settings (including humanitarian emergencies and climate disasters with loss of infrastructure) may be considered austere environments with similar resource allocation challenges. Some have defined “wilderness” as any physical location characterized by delayed or prolonged (over 1 h) patient transport to medical care. Victims of disasters where medical facilities and communications have been destroyed are part of this group.^49,50 Wilderness medicine programs focus on training to handle medical emergencies in remote settings where emergency services are not readily available.^51,52 However, all populations, including older adults, don’t have to travel to find such an environment. It can come to them in the form of heat waves, fires, and natural disasters. Disaster conditions can occur in urban, suburban, and rural locations and are all associated with delays in emergency response, extraction, and evacuation to medical resources. Diseases that are typical in wilderness or remote settings can emerge in the aftermath of disasters, including issues caused by degraded hygiene and water sanitation. ⁵³ Based on UN risk-reduction framework, triaging patients effectively during surge conditions is a critical skill for physicians and a foundational component of any disaster response effort; it is relevant to all medical specialties that may be called upon to assist with various sources of patient surges including the elderly. Physicians skilled in wilderness medicine are trained in these competencies. Since there are many commonalities between wilderness medicine and battlefield military medicine, the Wilderness Medical Society (WMS) has even collaborated with the military to create conferences and courses on the topic of transitioning military care, including triage skills, to that needed in nonmilitary but austere environments. ⁵⁴ Pandit suggests that although virtual reality equipment may be costly, online simulation overcomes resource barriers, is compatible with remote learning, and can make these skills accessible and scalable. ⁵⁵

Helping the most vulnerable populations will thus involve the education of multiple groups in multiple areas to develop necessary competencies, identification of workforce gaps, changes to graduate medical education program priorities, and education of trainees on the health and societal impacts of climate change.^38,56,57 According to Mallen, better understanding of the barriers and enablers to climate and health adaptation amid disruptions will help practitioners better anticipate and overcome such barriers, enhance adaptive capacity, and enhance local resilience. The Climate-Ready States and Cities Initiative grants and the BRACE (Building Resilience Against Climate Effects) framework can enhance these efforts. ⁵⁸

Most Americans feel global warming can be harmful to health but don’t understand how or who is most likely to be affected. ⁵⁸ Physicians and public health officials can educate them. ⁵⁹ This education is especially important for the elderly. Sixty percent of physicians cite lack of knowledge about climate as a reason they don’t address climate-related health concerns with patients.^60,61 Forty percent of physicians also report lack of time as a reason they don’t educate patients. ⁶⁰ Physicians can briefly review individual risks for these patients as part of disease prevention strategies. For medical providers wishing to learn more, see Appendix A. ⁶² Advances in the training of medical personnel have increased (see Appendix B).^62,63–75

There has also been a recent increase in wilderness medicine education at urban academic medical centers in areas not proximal to wilderness areas because of the increase in outdoor recreation and the increased recognition of disaster response as a top priority of the US government. ⁷⁵

Climate and health fellowships have been established at multiple institutions. ⁷⁶ Some of these address disaster risk strategies and health equity issues of geriatric patients but do not appear to address specifically the use of wilderness medicine skills in caring for the older patient.

LaFleur and Hood have conducted a hybrid fellowship in wilderness and telemedicine suggesting that in the future telemedicine will be an effective means for providing care in austere environments. ⁷⁷ This kind of advancement may be applicable to austere environments caused by natural disasters, especially when the elderly cannot be easily transported for care. Bandwidth remains a limiting factor for many austere settings.^78,79 The development of systems like T-Mobile/Starlink and SpaceMobile/ATT may play a future role here.

Conclusion

There should be collaboration of wilderness medicine and primary care educators with disaster and humanitarian relief organizations and search and rescue teams in modifying existing training to meet responders’ and patient's needs. Response agencies must recognize that training in wilderness medicine provides a background for practitioners working in dangerous and remote settings and ought to seek out individuals with such skills when placing responders in the field.^80,81

This education should include cross-training regarding the intersection of geriatrics and climate change, from the primary care physician helping patients with planning and training for wilderness travel and home emergency preparedness to the ED physician caring for patients with issues related to exacerbation of disease from climate change to all providers in the field (both in the wilderness or during natural disasters). Potential projects could include studies examining the skills of resource allocation in older patients, the development of educational techniques to teach those skills, and a more thoughtful examination of the intersection between wilderness medicine, public health, and disaster medicine, especially in the geriatric population. Climate change is making these intersections and the need for this education more urgent with time.

Supplemental Material

sj-docx-1-wem-10.1177_10806032241245399 - Supplemental material for The Intersection of Geriatrics, Climate Change, and Wilderness Medicine: Education is Critical

Supplemental material, sj-docx-1-wem-10.1177_10806032241245399 for The Intersection of Geriatrics, Climate Change, and Wilderness Medicine: Education is Critical by Mary Schaefer Badger in Wilderness & Environmental Medicine