Adirondoc – ADIRONDOC

Sun and Snow

February 1, 2023 adirondoc

2023, January/February Adirondac

In several recent columns, I have drawn attention to the problem of sun-induced skin injury-surprisingly, the major cause of death associated with outdoor recreation. It’s time for a reminder that sun protection is not just for the summer.

My introduction to the need for sun protection came while mountaineering in the Northern Cascades in late January one year. The combination of vast expanses of unshaded snow and ice, clear skies, absent pollution, and high altitude subjected us to intense UV exposure, both directly and reflected. Fortunately, we had been well schooled in sun protection and got through the expedition unscathed.

Although severe snow-enhanced sun injury is most common at higher altitudes, it can occur in any setting of clear skies and expansive snow fields. Thus, the Adirondack skier on a sunny day could be at risk.

How does the combination of altitude and snow create an enhanced risk of sun damage, even in winter? First, the atmosphere at altitude is less dense than that at sea level. This means that there is less opportunity for UV light to be absorbed and filtered before striking us. Similarly, alpine areas are generally less polluted, also allowing more UV radiation through. Of course, we also don’t have the luxury of taking a breather in the shade of trees while traversing a glacier.

The reflective nature of snow and ice also contributes to the problem. Dirt and vegetation absorb most of the sunlight striking them, while over 90 percent of light hitting clean snow is reflected. Thus, the winter climber is subjected to radiation both direct and reflected. The latter can hit spots about which we don’t typically worry in the summer: under the chin and in the nostrils, for example. Because of intense sunlight, coupled with dry cold air, the lips are also at great risk.

Fortunately, bitter temperatures force us to keep most of our skin well covered while traveling on snow and ice. What should we do for those areas that are exposed? As in the summer, sunscreens with SPF factors of thirty and above are the mainstay. Stopping to reapply sunscreen in cold, blowing snow is not pleasant, so I also recommend “barrier” types of sun protection; zinc oxide is a good example. These leave an impenetrable “paste” on exposed surfaces such as the nose and cheekbones. Don’t forget areas that can be hit by reflected snow, including under the chin and the interior of the nostrils.

Regular sunscreen or zinc oxide may not be practical or comfortable for the lips. Fortunately, there are lip balms with sunscreen; be sure to find one with an SPF of thirty or above. There are also specially formulated zinc oxide preparations suitable for mucous membranes such as the lips.

A final word about the importance of eye protection in snow and ice environments. The cornea is the “skin” of the eyes, and is particularly sensitive to UV radiation. Prolonged, unfiltered exposure can ultimately result in a horrible problem called “snow blindness,” an exquisitely painful condition which renders travel nearly impossible. Short of this problem, accumulated UV exposure can be a risk factor for early cataract development. Therefore, high-quality wrap-around sunglasses are an essential element for winter mountain travel. It even makes sense to have a spare along-at least one for the party. I have a pair of glacier glasses with side shields that transmit only about 10 percent of light hitting them; while these would be far too dark for July on Mt. Marcy, they are ideal for extreme winter mountaineering at altitude.

While hikers who confine themselves to the Northeast may not be as vulnerable as those at higher altitudes, they are still vulnerable. And the ADKer heading to the Rockies for some spring skiing may especially want to heed these warnings .

~Tom Welch, MD, is a physician at Upstate Medical University in Syracuse and an active member of the Wilderness Medical Society. He is a licensed professional guide and a certifying instructor for the Wilderness Education Association, and has guided groups in the Adirondacks, Montana, and Alaska. More information is available at his website and blog, adirondoc.com.

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Topics: Environmental Injuries, General First Aid, Skin, Sunburn

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Hiking on Drugs

December 1, 2022 adirondoc

2022, November/December Adirondac

No, not those drugs …
Hypertension (high blood pressure), a major cause of cardiovascular death affects over 100 million Americans, 80 percent of whom are on medication for the problem. As I have discussed in other columns, aerobic exercise such as wilderness travel has a major positive impact on hypertension. This observation is tempered by the fact that several of the common medications used for hypertension may affect the hiker negatively. Although this is not a reason to avoid wilderness pursuits, being aware of the effects of several types of antihypertensives can help one prepare to enjoy a trek without nasty complications.

There are literally hundreds of individual antihypertensive drugs. I will focus on four categories that include the vast bulk of prescription medicines for hypertension and have specific concerns for backcountry use. I will avoid using names of the individual drugs since there are so many of them. Readers should check with their pharmacist or provider (or, of course, Google) to learn into which categories their own prescriptions fall.

The group of drugs that may be the most problematic are the beta blockers. These drugs lower blood pressure by interfering with the strength and rate with which the heart beats. They are highly effective medications, and particularly beneficial for those with prior heart attacks.

Most individuals experience fatigue and lowered exercise capacity when beginning beta blockers, although these effects may lessen with time. For some, however, beta blockers make strenuous exercise such as climbing a peak nearly impossible. Hiking requires an increase in the rate and strength of the heart’s contractions; this increase may be severely limited by beta blockers. Regardless of one’s prior experience, it would be unwise to plan a major hiking trip after starting a beta blocker without having a good idea of one’s current exercise capacity This would best be assessed by a series of hikes of gradually increasing length and difficulty.

There are a number of specific beta blockers, which vary in their impact on exercise capacity. This would be an important discussion with one’s provider before beginning the drug.

Diuretics are a group of drugs that increase urine output, lowering blood pressure by reducing blood volume. After being on a diuretic for a while most patients reach a new equilibrium of fluid balance and are generally comfortable.

Trekking, however, can upset this equilibrium by increasing the need for fluids. Thus, there may be a greater risk of dehydration for hikers taking diuretics. This may show itself with fatigue, light-headedness, and excessive thirst. Hikers experiencing such symptoms while taking diuretic, should increase their intake of fluids such as water, as well as salty snacks. As with many such things, there is no real “rule” for doing this, besides carefully heeding the signals of one’s own body.

Angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin receptor blockers (ARBs) are two different categories of antihypertensive that have similar mechanisms of action. These drugs inhibit a hormone that typically constricts blood vessels, thus lowering blood pressure. This effect may interfere with the body’s usual ability to raise blood pressure upon standing or becoming slightly dehydrated. Patients may therefore experience dizziness or lightheadedness when getting to a standing position or upon arising in the morning. While annoying, this is seldom dangerous. It is wise to be careful moving to stand, such as after stopping on the trail for a rest. One should also avoid dehydration while on these drugs.

Calcium channel blockers relax the tension in blood vessels, lowering blood pressure. Like ACE inhibitors and ARBs, these drugs may render one lightheaded upon standing, especially if slightly dehydrated.

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Topics: Diet & Nutrition, Drugs, General First Aid

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Clots

October 17, 2022 Tom Welch

2022, September/October Adirondac

When a trivial injury results in some minor bleeding, our body activates a system for stopping the bleeding. Our coagulation system is truly a wonder. As blood flows through arteries, veins, and organs, it (usually) is unimpeded. Yet, as soon as a blood vessel is damaged or opened, a powerful cascade is set in place, the ultimate result of which is a clot that stops the bleeding. As the injured tissue is repaired, another cascade is activated in order to dissolve the clot. The entire process of clot formation-thrombosis- and clot dissolution-thrombolysis- requires the interplay of scores of individual proteins and cells, working in concert. As with any complex system, however, the thrombosis/thrombolysis mechanisms occasionally go awry.

One of the more common disruptions of the coagulation system is the formation of a blood clot in a large blood vessel in the absence of injury or bleeding. This condition is referred to as a deep vein thrombosis (DVT), and can have effects ranging from annoying to life-threatening.

The first sign of a DVT is usually swelling in the part of the body downward from the clot, often painless. A DVT in the large vessels of the leg, for example, may first show as painless swelling of the foot.

Once a DVT gets started, it often tends to grow in size and involve more of the vessel On occasion, part of the clot can break loose and begin to travel elsewhere in the body. At this point, the clot becomes an embolism and dire consequences can ensue. Most concerningly, the clot can become lodged in the lungs as a pulmonary embolism, resulting in severe pain, shortness of breath, and even sudden death.

Several factors can predispose one to the development of a DVT. Occasionally, an inherited defect in one of the components of the coagulation system may lead to a proneness to spontaneous clot formation. More commonly, prolonged positioning without movement is the culprit in DVT formation; this is why long airline flights in cramped seats are a notorious trigger for leg DVTs. Dehydration can also become a factor in DVT formation, by making blood cells more concentrated and “thick” Certain medications, such as oral contraceptives, may also predispose to the formation of spontaneous clots.

Backpackers’ concerns
What about the backpacker? The nature of hiking makes leg DVTs an unlikely event, although travel to the !railhead itself can be a risk Getting out of one’s vehicle for a quick drink of water and a stretch is a wise preventive. There are, however, several reports of DVTs in the blood vessel of the upper arm, the subclavian vein, in backpackers.

The mechanics of most backpack shoulder straps result in continuous pressure on the subclavian vein. If one combines this with dehydration, limited arm movement, or other DVT risk factors, such as medication use, clots could develop in one or both arms.

Preventing DVTs during backcountry travel (including on the way to the trailhead) involves some simple steps. Ensuring adequate hydration is a major one-indeed, it seems important in preventing a host of wilderness medical disruptions. One should pay close attention to backpack fit, and adjust the shoulder or chest straps if one feels heavy pressure on the area just below the collarbone. The backpack should come off at rest stops, and vigorous range-of-motion exercises of the shoulder should be done to ensure circulation. If one has a personal family history of DVTs, or is taking a medication that could increase the DVT risk, consultation with one’s provider before a trek would be wise.

First aid options for backcountry DVTs are limited. If one were to notice increasing swelling of the arms, beyond the fairly typical slight finger swelling most of us experience, a DVT should be suspected. Offloading the pack to one’s companions, ensuring hydration, and planning trek termination for definitive care are the only practical options. Although there is no evidence basis for the recommendation, taking a “baby aspirin” (81 mg) may be useful in attenuating progression of the clot, and has no real downside. In the event of symptoms of pulmonary embolism (cough, chest pain, shortness of breath, coughing blood), urgent evacuation is mandatory.

The CDC has a very helpful summary of DVT prevention available on its website, cdc.gov /ncbddd/ dvt/ facts.html.

Tom Welch, MD; is a physician at Upstate Medical University in Syracuse and an active member of the Wilderness Medical Society. He is a licensed professional guide and certifying instructor for the Wilderness Education Association, and has guided groups in the Adirondacks, Montana, and Alaska. More information is available at his website and blog, adirondoc.com.

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Topics: General First Aid, Head & Neck

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Wilderness Evacuations

August 20, 2022 Tom Welch

2022, July/August Adirondac

Trigger warning: Some readers may find this content gross.
Lots has been written, very importantly, on the safe and proper handling of human waste in the backcountry. That won’t be the subject here. We will discuss the mechanics of passing said human waste, or more to the point, difficulty in passing-constipation.

Constipation is defined as infrequent bowel movements (typically less than three per week). More important, it is associated with stools that are sometimes hard to pass, often with the sensation that the bowels did not empty completely. Severe constipation may be accompanied by abdominal pain and can lead to additional problems such as worsening hemorrhoids. According to a study from over a decade ago, constipation in the U.S. accounted for nearly six million physician visits and about $235 million in direct costs in a year. These figures have likely grown significantly since the study was published.

Why would this be a topic for a column on backcountry health and safety? There are a few reasons. First, the person with constipation at home can at least sit in relative comfort in a warm, dry room, reading a magazine such as this one. Squatting over a cathole in the rain or in black fly season, however, is a whole other experience. More serious constipation can result in abdominal pain that can be severe enough to be confused with appendicitis; there are documented wilderness evacuations from this problem. Finally, three major contributors to constipation (diet, hydration, and exercise) may be significantly affected by backpacking. This may result in a significant change in bowel habits for someone who ventures into the backcountry for a few days.

The substance in our diet that most helps to maintain the bulk and softness of our stools is fiber. Fiber content is listed in the nutrition information panel on most foods. Although the data are not firm, thirty grams per day represents a good fiber intake for most adults; this is not likely achieved by most Americans. Good sources of fiber include whole grains, oatmeal, dried fruits, nuts, and brown rice.

For many people, the backpacking diet may differ considerably from that at home. Some folks, for example, like to subsist with the relative simplicity of boxed “mac and cheese,” instant white rice, hard white rolls, and similar meals on the trail. While this may simplify meal preparation, it is a recipe for constipation-especially on a trek of more than a couple of days. As readers may ]mow from my other writings, I am a big proponent of healthier eating on the trail, like that described in resources such as NOLS Cookery. I have had students in my wilderness courses whose usual diets were low in fiber think that something was wrong after a few days of healthy trail eating upon finding that they were having one or two soft stools daily.

Hydration is the second factor impacting constipation. When one is dehydrated, the body absorbs as much water as possible from the gut, making stools drier and harder. Yet another reason to stay well hydrated in the backcountry! Remember, there is no “one size fits all” rule for liquid intake; one should drink as much as necessary to keep urine from being dark yellow.

Exercise is the final important factor in preventing constipation. Sedentary folks are at much greater risk, so maintaining bowel health is another good reason to hit the trail.

The backpacker with normal bowel habits at home who consumes a healthy trail diet and plenty of water should have no difficulty with constipation on the trail. Folks prone to constipation, or those with less fiber-rich diets, may want to bring along some medication for constipation. There are many types of these; the most common are stool softeners (such as Colace) and stimulants (such as Dulcolax). Stool softeners are less likely to result in a “quick need” to have a bowel movement, and are therefore a better choice on a trek.

The American Gastroenterological Association has a very helpful online resource with additional information about constipation, including warning signs of more serious problems. It can be accessed at patient.gastro.org/ constipation.

Tom Welch, M.D., is a physician at Upstate Medical University in Syracuse and an active member of the Wilderness Medical Society. He is a licensed professional guide and certifying instructor for the Wilderness Education Association, and has guided groups in the Adirondacks, Montana, and Alaska. More information is available at his website and blog, adirondoc.com. Bill Balistreri, M.D., an internationally known expert in constipation and other gastroenterological disorders, reviewed this column and provided helpful advice.

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Topics: Diet & Nutrition

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High Time

June 22, 2022 Tom Welch

2022, May/June Adirondac

After twenty-three years of writing this column, some overlap of subject matter is probably inevitable. I am going to discuss a topic I reviewed on these pages over two decades ago. Although there is very little new science about the subject, it will be a good reminder for the older reader and a good introduction for a new generation of trekkers.

Every now and then, I encounter a hiker huffing and puffing en route to an Adirondack summit and making a comment along the lines of ”.Air is pretty thin up here, eh?” While that’s technically correct, the implication that the hiker’s exhaustion is a function of altitude is not. This does not imply, however1 that altitude is never a problem for the trekker-it most assuredly can be!

Every bodily function requires oxygen. Oxygen is delivered continuously to the muscles, brain, and other organs by red blood cells. These cells pick up oxygen as they flow through the lungs and deliver it through the network of blood vessels. After offloading oxygen to tissues, the cells return to the lungs for a resupply.

The amount of oxygen that a red blood cell can take up from the lungs is a function of two things: the percent of oxygen in the air, and the air pressure. As one ascends, the percentage of oxygen in air is constant, but the air pressure decreases; this is why commercial aircraft, flying at very high altitude, are pressurized.

Although air pressure decreases incrementally for every foot of elevation gain, the consequence for red blood cell oxygen delivery in healthy persons is inconsequential below about 8,000 feet. This is why folks climbing Mt. Marcy ( or any peak east of the Mississippi) can’t blame altitude for their fatigue. A ski vacation in the Rockies, or an alpine or Himalayan trek, is a very different story.

The medical effects of high altitude are all direct consequences of tissue oxygen deficiency. The earliest effect most folks notice is a lower threshold for exhaustion-becoming unusually fatigued by what seems like minimal effort. The body compensates for impaired oxygen delivery by increasing the respiratory rate and the heart rate (pulse). This is why one feels (and appears) much more “winded” by a jaunt in the Rockies than one of similar length and elevation change in the Adirondacks. There is no real “treatment” for this problem beyond factoring it into your trip planning.

Acute mountain sickness (AMS) is the next step in altitude illness. It is marked by headache, occasionally very severe, accompanied by some systemic complaint such as nausea, extreme fatigue, or lightheadedness. Many New Yorkers who make quick trips for Colorado ski vacations experience AMS, which they may attribute to hangover! (Actually, alcohol can worsen AMS.)

More severe altitude complications generally start at or above 11,000 feet. High-altitude cerebral edema (HACE) refers to brain swelling, which results in deterioration in mental function, delirium, and coma. Accumulation of fluid in the lungs, with cough, bloody sputum, and severe respiratory distress are the findings of high-altitude pulmonary edema (HAPE). Both of these conditions are life-threatening.

The most important preventive measure for altitude illness is allowing time for acclimatization. Once above about 11,000 feet, one should never sleep at a gain of more than 1,500 feet in a day. Extended climbs above this altitude should include a full rest day out of every three or four. Attention to hydration is important; one becomes dehydrated more easily at high altitude, and AMS, HACE, and HAPE are all worsened by dehydration.

Simple high-altitude headache typically responds to NSAIDS and fluids. There are additional prescription medications (acetazolamide and dexamethasone) useful for AMS and other complications. The only definitive therapy for severe altitude illness is descent; even seemingly severe symptoms seem to melt away upon a descent of a few thousand feet. Major expeditions may carry supplemental oxygen, or even portable hyperbaric devices, but neither are substitutes for rapid descent.

I always recommend consultation with a wilderness or travel medicine specialist prior to undertaking an extended, sojourn at very high altitude. Often, these physicians will provide prescriptions for possible use in the event of symptoms; they can also counsel folks with chronic conditions that could be worsened by high-altitude travel, or would make such treks unwise.

Tom Welch, MD, is a physician at Upstate Medical University in Syracuse and an active member of the Wilderness Medical Society. He is a licensed professional guide and a certifying instructor for the Wilderness Education Association, and has guided groups in the Adirondacks, Montana, and Alaska. More information is available at his website and blog, adirondoc.com.

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Topics: Altitude, General First Aid

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“Shin Splints”

March 10, 2022 Tom Welch

2022, March/April Adirondac

One of the ironies of modern medicine is that it sometimes seems that little attention is devoted to the things that bother folks the most. “Shin splints” are a terrific example of this. I put the term in quotes since there isn’t complete agreement among experts on what to call the condition. The currently preferred terminology among orthopedists and sports medicine specialists is “medial tibial stress syndrome” (MTSS). I’ll stick to “shin splints.”

Most of us have a pretty good idea what shin splints are, often from personal- experience. The condition causes pain along the inner border of the tibia, the most prominent bone in the front of the lower leg. It typically develops after strenuous exercise, most often running but also hiking. Hiking which produces a lot of impact (such as walking down a steep trail) can be a particular culprit. It typically comes on during exercise, and remits somewhat after rest. With time, however, it may continue even after active exercise has stopped.

Several muscles involved in walking attach to the inner surface of the tibia, and it is believed that constant pulling of these muscles on the surface of the bone is the cause of the pain. There is really no laboratory or x–ray test which is positive with shin splints.

The diagnosis is primarily made by the history. Unlike the sudden pain of something like a sprained ankle, shin splints develop gradually during exercise. The discomfort generally extends from the middle of the bone upward and downward. There is typically no single spot at which tenderness is located; rather, pain extends quite a bit along the entire bone. There is rarely any swelling or bruising over the painful area, but it may be somewhat painful to palpation. Again, however, the pain usually extends over a few inches of the inside of the bone.

Beyond rest, there is really no definitive treatment for shin splints. The old standby medication, NSAIDS such as Advil or Aleve, may provide some relief. Although unquestionably uncomfortable, shin splints rarely are disabling. Most hikers can continue their trip, albeit at a perhaps slower and gentler pace. For most casual hikers, shin splints are little more than an inconvenience. For some competitive runners, however, the condition may result in the loss of an entire season.

For those predisposed to shin splints, prevention may involve modulating the choice of terrain and hike length. Although some advocate the use of a cushioning insole (orthotic), there is no strong evidence basis for this recommendation. It can’t hurt, however.

Finally, a few things can beconfused with shin splints. Lower leg fractures are associated with a definite injury, and typically have exquisite point tenderness. A special type of fracture, “stress fracture” is an exception. These are tiny hairline cracks in the bone which result from continuous “micro trauma.” Stress fractures are more likely to persist after exercise stops, and may be more painful upon palpation. From a practical standpoint in the field, there is no real difference in management from shin splints.

Far more dangerous is compartment syndrome. This refers to swelling of or bleeding into muscles that are contained by firm tissue (“fascia”). Although it typically follows injury, compartment syndrome has occasionally been reported after unaccustomed exertion. Unfortunately, one of the common locations is in the muscle groups of the lower leg, similar to the area involved in shin splints. The pain is far more severe than that of shin splints, and does not remit upon stopping exercise. The affected area is quite tender, and may be swollen. There is typically weakness of the involved muscles, and pain if they are stretched. The pressure within the muscles can result in permanent injury. Urgent evacuation for definitive care is the only field treatment.

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Topics: Environmental Injuries, General First Aid, Orthopedics

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Life in Balance

January 26, 2022 Tom Welch

2022, January/February Adirondac

“Wilderness medicine” is about a lot more than splinting complex fractures on steep slopes in a snowstorm. Much of the specialty should deal with prevention of injuries and encouragement of fitness. Fitness and wilderness trekking are closely interrelated; outdoor adventure pursuits are a terrific way to maintain one’s fitness, and physically fit adventurers are less likely to require wilderness medical treatment.

When we think of fitness for hiking, strength and endurance are probably the first things we consider. For this column, though, I want to remind readers about balance.

Two of the most common injuries in hikers, ankle sprains and forearm (Colles) fractures, are typically triggered by a momentary loss of balance, resulting in a slip or fall. Although this can happen to anyone, some individuals are plagued by balance difficulties. While a host of factors contribute to balance disorders, most can be treated or prevented.

Underlying joint problems, such as knee osteoarthritis, are a common antecedent to balance difficulties. Pain or limited movement of a joint may make one compensate with awkward movements, leading to an unstable position and loss of balance. This is one of the reasons I highly recommend trekking poles for folks with such problems (see “AdironDoc,” March-April 2021).

Blood pressure problems or the use of certain medications may cause temporary decreases in brain blood flow, especially with a sudden change in position such as getting up from a rest. This can result in momentary lightheadedness and a stumble.

Balance requires a sensation of position, something we inelegantly refer to as “proprioception.” Many factors, including aging, can contribute to diminished proprioception.

Balance also requires the function of a complicated apparatus in our inner ear, the “vestibular system.” This is the system that makes one dizzy after amusement park rides or queasy on a boat. Head injuries, illnesses, and (again, unfortunately) aging can impact vestibular function.

A visit to one’s primary care provider is the way to begin addressing issues affecting balance. Many balance problems can be uncovered by a careful medical history and exam. Depending upon the issues, treatments ranging from physical therapy to medication may be prescribed. For example, there are now physical therapists who specialize in customized exercise programs for individuals ,-vith balance problems caused by inner ear abnormalities (“vestibular rehabilitation”).

For folks without overt balance problems who are interested in maintaining or improving their balance, there are a number of terrific options. One particularly worth mentioning is tai chi. This ancient Chinese practice, which frankly looks a bit odd the first time one observes it, is a gentle form of exercise that has measurable positive effects on balance, as well as a host of other benefits. A nice description of these was provided in a Harvard Health blog (health.harvard.edu/ staying-healthy /the-health-benefitsof- tai-chi). Although there are videos that can teach tai chi at home, I suggest starting with a group class. These are frequently available through community centers, senior programs, and gyms.

For some reason, many folks are attracted to the drama of wilderness medicine. How exciting to diagnose a Colles fracture just below timberline on a high peak, shortly before sunset! How thrilling to package the patient to prevent hypothermia and splint the fracture while observing for shock and ensuring hydration! How exhilarating to orchestrate an early-morning helicopter evacuation! Contrast this to the abject dullness of recommending a tai chi class, which could have prevented all the drama. The best medicine is often the least exciting.

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Topics: Environmental Injuries, Readiness

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Too Hot to Handle?

November 11, 2021 Tom Welch

2021, November/December Adirondac

I WRITE THIS COLUMN as we end one of the warmest summers in memory. All indications are that this sorry trend is going to continue. As the climate warms, heat injuries become increasingly important, and not only for hikers and paddlers. Any season of the year is now a good time to discuss such injuries as we plan for travel in warmer climes or for next summer’s weather.

As with any health issue, we need to begin by understanding some science. The countless metabolic functions that make human life possible all require a fairly narrow range of temperature to operate optimally. For this reason, evolution has equipped our bodies v.rith many mechanisms for cooling (for example, sweating) and warming (shivering). Cold illnesses (hypothermia) occur when the warming mechanisms are overstressed, while heat illnesses (heat exhaustion and heat stroke) result from failure of the cooling mechanisms.

As we exercise in a hot environment, we begin to sweat. Since evaporation results in cooling, the evaporation of sweat from our skin has a cooling effect, especially if low humidity or a breeze facilitate evaporation. Blood flow to the skin increases, further facilitating the removal of heat from the body. If the ambient temperature and humidity are high, these mechanisms are compromised and less efficient.

Heat exhaustion develops when the body’s attempts at compensation for heat stress begin to fail, often precipitated by dehydration related to sweating and loss of fluid in breath. The symptoms of heat exhaustion range from mild fatigue and lightheadedness to severe headache, weakness, and fainting. The patient with heat exhaustion will typically feel cold and clammy because of intact sweating; body temperature is normal or only slightly elevated. He or she is likely to be very thirsty.

Field treatment of heat exhaustion is relatively simple, and based on the underlying physiology. Exertion needs to stop, which means sitting in a shady spot and taking off the pack. The need is for both salt and water. Oral rehydration solutions (mixtures of water with optimal mineral and glucose content) are available, but not typically carried on wilderness treks. My suggestion is water alternated with salty snacks such as peanuts. Using water alone for heat illness risks the development of low body sodium (hyponatremia), a potentially fatal affliction I discussed in my November-December 2020 column. More severe cases may require hospitalization for intravenous fluid replacement.

Heat exhaustion occurs on a spectrum, and most cases are relatively minor. I suspect that many readers of this column have “survived” mild heat exhaustion with no treatment other than rest and drinking.

Heat stroke is an entirely different matter. In patients with heat stroke, there has been a complete breakdown of the body’s cooling mechanisms. This results in severe elevations in temperature, with consequent failure of many body systems. Victims of heat stroke are hot and dry (because sweating is no longer operative), with extremely elevated body temperatures. They are likely to be delirious or unconscious, and the condition may progress into cardiorespiratory, liver, and kidney failure.

True heat stroke in the wilderness is most unlikely, and meaningful survival would be impossible. Treatment in even the most high-tech setting is complex; in austere environments, external cooling with copious amounts of water, immersion if feasible, and attention to the “ABCs” of resuscitation are about all that can be done pending evacuation.

Although progression from heat exhaustion to heat stroke may occur, it is unusual; most heat stroke occurs in very specific contexts. Endurance athletes, military recruits, and similar folks undertaking strenuous exercise (which generates body heat) in hot weather (which compromises dissipation of heat) are at great risk. Elderly or disabled individuals living in very hot environments and unable to maintain hydration and other selfcare activities are a second risk group. Sadly, we can expect more of the latter as climate change progresses.

Further information on heat illness is available in the clinical practice guidelines of the Wilderness Medicine Society at wemjournal.org/article/ S1080-6032(18)30199-6/fulltext.

~ Tom Welch, MD, is a physician at Upstate Medical University in Syracuse and an active member of the Wilderness Medical Society. He is a licensed professional guide and a certifying instructor for the Wilderness Education Association, and has guided groups in the Adirondacks, Montana, and Alaska. More information is available at his website and blog, adirondoc.com.

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Topics: General First Aid, Water

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How Sweet It Is: Tips for hiking safely with diabetes

September 14, 2021 Tom Welch

2021, September/October Adirondac

DIABETES MELLITUS is one of the most common chronic health conditions, and a major contributor to premature death. In addition to the effects of the disease itself, diabetes increases the risk and severity of a number of other conditions, including cardiovascular disease, stroke, and chronic kidney disease. Globally, about half a billion people may be affected by diabetes.

"ANOTHER DAY AT THE OFFICE" — zack clothier: The view from my campsite along the Nun-Da-Ga-O Ridge as the afterglow from sunset slowly fades into the night.

The basic defect in diabetes is in the body’s ability to utilize glucose as a source of energy. This results in a rise in blood glucose (“sugar”) levels. The defect is caused by a decrease in either the ability of the pancreas to produce insulin (the hormone central for the use of glucose as a fuel) or the body’s ability to utilize insulin. The former is “type 1” diabetes; the latter is “type 2.” Type 1 diabetes requires the use of injectable insulin, and most often develops in children and adolescents; type 2 (far more common) typically develops in adults and is usually managed with diet and medication other than insulin. While the prevalence of both types of diabetes is increasing, this is especially the case for type 2 disease. Rising obesity levels are a major cause of this.

Exercise is very important in the management of diabetes, because it both improves glucose metabolism and may help with weight control. Exercise is also important in averting some of the complications of diabetes, such as cardiovascular disease. Outdoor adventure travel, thus, can be very beneficial for folks with diabetes, although it is very important to discuss this in detail with one’s diabetes specialist.

A few issues that are important to any hiker or camper are particularly important for people with diabetes. Suboptimal control of the disease may make one more susceptible to poor healing, especially of foot wounds. Blister prevention and early treatment are important in every hiker, but particularly so in those with diabetes. Careful meal-planning is critical in managing diabetes, and the increased caloric needs of backpacking need to be factored into this. The treatment of diabetes renders many patients susceptible to episodes of hypoglycemia (low blood sugar). Hypoglycemia can be dangerous if not treated immediately, and the treatment commonly is the administration of some form of oral sugar (although some non-sugar drug alternatives are now available). While the principles of bear avoidance require the removal of such items from one’s tent, I would make an exception for patients with diabetes. One simply cannot be exiting the tent and rooting around in the bear-resistant food container in the middle of the night to secure emergency hypoglycemia treatment!

For decades, I taught wilderness medicine students that wilderness expeditions, even overnight camping, were not feasible for folks with type 1 diabetes. The logistics of storing insulin, regular blood testing, and responding to dramatic changes in diet and energy expenditure were simply too complex for much beyond a’ brief overnight trip. Happily, recent developments have proven me very wrong. Individuals with type 1 diabetes regularly compete at high levels in such strenuous activities as triathlons and ultramarathons. A few people with type 1 diabetes have even successfully summitted Mt. Everest. Extended trips in austere environments are no longer out of the question.

Much of this change has resulted from major technologic achievements, including programmable insulin pumps, continuous glucose monitors, and easily transportable cold storage units. That being said, the logistics involved in such treks are daunting, not least because the energy requirements of backpacking may increase daily calorie needs by a factor of three or more, necessitating major changes in insulin dosing. Such treks require careful planning with a diabetes specialist who is familiar with the demands of adventure travel. Such an individual may be difficult to find, although major diabetes centers can probably help locate an appropriate specialist. It will also be important to have a companion along who is familiar enough with diabetes to be of assistance in emergencies .

Tom Welch, MD, is a physician at Upstate Medical University in Syracuse and an active member of the Wilderness Medical Society. He is a licensed professional guide, and a certifying instructor for the Wilderness Education Association, and has guided groups in the Adirondacks, Montana, and Alaska. More information is available at his website and blog, adirondoc.com. Roberto Izquierdo, MD, a senior adult and child diabetes specialist at Upstate Medical University and the Joslin Diabetes Center in Syracuse, reviewed this column and provided very helpful suggestions.

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Topics: Diet & Nutrition, Disease

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Another Reason to Hate Ticks

July 15, 2021 Tom Welch

2021, July/August Adirondac

READERS COULD BE forgiven for wondering “What more could he possibly have to say about ticks?” Indeed, the wilderness medicine literature is replete with articles on the subject. For most tick-borne diseases, the paradigm is the same: Tick bites mammal and acquires an organism. Tick then bites human and passes on organism. Organism causes disease in human. The disease can be treated, but preventing tick bites is the best strategy. For everything from Lyme disease to Colorado tick fever, these four sentences pretty much summarize the situation.

Now, for something completely different: alpha gal syndrome (AGS).

Although AGS as a complication of tick bites has been reported in a number of esoteric medical journals over the past few years, it has remained a medical curiosity. A recent case report in the widely circulated New England Journal of Medicine (N Engl J Med 2021;384:462-7) may give the condition greater visibility.

Unlike most tick-related disorders, which are infections, AGS is an allergic reaction to a molecule, alpha gal for short, which is present in all mammals except primates (like us). This includes animals in our diet such as cows and pigs. Ticks may ingest tiny quantities of alpha gal when feasting on deer, then may transfer some of the material to their next human host. Some humans, upon being exposed to alpha gal from a tick bite, develop antibodies to it in large enough quantities to produce an allergic reaction upon consumption of red meat. Interestingly, the reaction seems to be specific to the meat; patients with AGS after consumption of beef generally can tolerate milk.

We have no idea why only a subset of folks suffering tick bites develop these antibodies and AGS. Although in theory any tick can transmit alpha gal, thus far the problem seems limited mostly to the lone star tick, a species seen in New York.

The symptoms of AGS are quite variable. Some patients develop an itchy rash, urticaria (“hives”), following meat ingestion. Unlike other food allergies, this may be delayed in onset. Patients have described awakening from sleep with hives after a red meat dinner, for example. Other reactions may be more specific to the intestinal tract, with abdominal pain or diarrhea, similar to other forms of food intolerance.

Although unusual, more dramatic symptoms can occur with this disorder. The rare patient can experience swelling of the lips (angioedema), difficulty breathing, and even the severe generalized allergic reaction called anaphylaxis. Without immediate treatment, such individuals can die.

Like the rest of the tick-related disorders, AGS is prevented by the whole suite of tick avoidance measures to which users of the outdoors are becoming accustomed. Once it has developed, prevention involves avoidance of meat. Although as a vegetarian for decades I would not find this difficult, my carnivorous friends tell me it can be a burden! Mild reactions to alpha gal respond to over-the-counter antihistamine medications such as Benadryl®. More severe reactions may require the administration of steroids. Like anaphylaxis from any allergen, life-threatening reactions require the immediate administration of epinephrine, such as from an EpiPen®.

Since the symptoms of AGS are somewhat vague, and since they may not allows follow meat ingestion immediately, the condition is often difficult to diagnose. Many patients report years passed before a definite diagnosis was made. Users of the outdoors who have had tick exposures (the frequency of the condition increases with the number of tick bites) and who experience unexplained allergic symptoms such as hives should mention their tick exposures to their primary physician or allergist. There are both blood tests and skin tests which can be used to confirm the diagnosis of AGS.

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Topics: General First Aid

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