Originally published in the 8/20/15 edition of Out There Monthly
As the temperatures heat up for the summer, many people find themselves reaching more frequently for their water bottles. As we look towards maintaining high performance and enjoyment of outdoor activities in the summer heat,, we need to be consistently aware of our hydration levels, particularly as our normal body functions result in the loss of a portion - most noticeable through sweating - of the 50-70% of our body weight that is made up of water each day.
Proper hydration can be estimated with three factors; urine output, thirst and body weight. Proper hydration can be identified by regular with a clear to light yellow color urine. Infrequent urination with dark colored urine and a strong odor can be an indicator of dehydration. Since thirst will present after the body is already in a dehydrated state, it is best to hydrate prior to feeling thirst. Significant body weight change after strenuous activity can indicate dehydration or over-hydration. Experiencing one of these indicators independently should lead you to consider dehydration, and any combination (or all three) increase the likelihood of dehydration.
There are two specific medical conditions associated with hydration and outdoor activity to be aware of when planning outdoor activities; dehydration and hyponatremia. Both conditions present with similar symptoms and are more common as the temperature and activity increase.
During high levels of exertion in warm environments individuals can lose up to 2 liters of water per hour. Although most of us will lose less water than that per hour, we still can easily lose water faster than we are able to rehydrate since our absorption rate is about .5 liters per hour. As the body becomes dehydrated, symptoms will start with increasing thirst, then increase to include fatigue, headache, nausea and decreased athletic performance. As dehydration increases, people experience dizziness and a decreased ability to sweat. If dehydration becomes profound, a person can go into shock.
The combination of sweating excessively and intaking more water than the body can process can result in a decreased sodium (salt) level in the body, a condition called hyponatremia. Hyponatremia most commonly develops from prolonged activity in warm environments while drinking plain water for fluid replacement. It can also occur from attempting to drink too much water in anticipation of high levels of activity or heat. As a person loses salt through sweat or decreases the balance of salt from over-hydration symptoms begin to present that are similar to dehydration. Fatigue and headache can be early indicators followed by muscle cramps. Increase in urine output (often clear) can also occur. In the extreme cases people experience personality changes and loss of consciousness.
The key to avoiding dehydration is to hydrate appropriately prior to the start of any activity. To avoid water issues onr upcoming adventures, plan on drinking consistently, but not excessively. Aim for consuming .25-.5L per hour. To avoid hyponatremia during high output activities, consider adding an electrolyte mix to plain water, but watch out for highly sugared electrolyte mixes that might be more akin to drinking a candy bar. If drinking plain water, plan to include small, frequent snacks that include sodium.
If symptoms of a hydration-related illness occur, proper treatment will start with understanding the history of food and water intake of the person affected. For a person with symptoms and a history of limited water intake, physical activity should be decreased and fluids encouraged at a rate of .5 liters per hour. If the affected person has a history of prolonged exertion and has been drinking plain water, consider hyponatremia and treat by discontinuing water consumption and slowly increasing the person’s sodium intake.
Many years ago, I found myself on a camping trip hunkered down on a foam mat trying to find safety from the storm overhead. To this day, I still have memories of my hair standing up on end, the smell of ozone and the rattle of metal objects during that storm. Since that storm, I have found myself in far too many thunderstorms while traveling in remote environments. Some of the storms were closer than others, but each inspiring awe, fear and a good dose of respect.
The most challenging part about being in a lightning storm is the lack of predictability of the strikes. Lightning is random; it can strike in the same place twice, does not always hit the tallest object, and can travel horizontally from storms striking a location with blue skies overhead. This unpredictability combined with the violence of the lightning should produce respect and caution in even the most well traveled adventurer.
Lighting can strike people in two ways - direct strikes and through a ground current. Direct strikes occur when the lightning passes through the body of the person being hit, producing both entrance and exit wounds. Ground currents are strikes from an electrical charge caused by a near by strike that travels through the ground and are responsible for the majority of lightning produced injuries.
The best prevention is to not be outside when a lightning storm hits, however this is not practical for people the recreate outside. Knowing local weather patterns can provide some knowledge of when to travel and, more importantly, when not to travel in lightning prone areas. Learning to read weather to predict the arrival of the cumulonimbus clouds (tall clouds that produce lightning) provides the ability to move towards a safer location prior to the arrival of a storm. In settings where visibility is limited by a mountain or cliff, having and using a barometer to detect changes in the atmospheric pressure allows for warning that a storm is approaching.
You can track the progress of the storm toward or away from you by counting the time between the flash of lightning and the boom of thunder. The storm is one mile away for every five seconds between the light and the noise. If the count between the flash and the boom is getting smaller the storm is moving closer; if the count is getting longer the storm is moving farther away.
If you find yourself in a thunderstorm there are a few things you can do to reduce your risk exposure. If you are close enough to hear the thunder you are close enough to get struck. Start by getting to a “safer” location: summits, ridges, hilltops, and bodies of water are all less desirable than valleys and low-lying areas. Find a low-lying area ideally with a group of trees that are a similar height; avoid being under or near a lone tree. Next, reduce your exposure to ground currents by insulating yourself from the ground by crouching, kneeling or sitting (preference is in that order) on a sleeping pad or backpack in order to limit your contact with the ground.
Lightning injuries are caused by the heat, electrical charge and concussive force of the lightning. Injuries include cardiac or respiratory arrest, loss of hearing and/or vision, burns, and nervous system dysfunction. Many of the injuries can be stabilized with first aid and early high quality CPR for individuals who do not have a pulse and are not breathing or not breathing normally. Regardless of the severity of injury, anyone who is suspected of being struck by lighting should be evacuated to a hospital for further evaluation.
Even with wilderness medicine training and an appropriately stocked first aid kit, the best first aid is always prevention. When spending time outdoors this summer, be sure to keep an eye on the sky to watch for the build up of cumulonimbus clouds. Understand the local weather patterns and have a plan for how to get yourself to a less exposed place if the storm continues to build.
When I first walked into the classroom, the people seemed like any other wilderness medicine students – paying rapt attention to the words of the instructors as they prepared to move from a lecture to practicing skills in a scenario. Yet the questions that pepper the instructors are clearly those of people with significant medical training as they dive further into the physiology behind common medical issues seen in the wilderness and ask questions about how medical procedures used in a medical setting can be improvised in the field. Welcome to the Wilderness Medicine Elective, where fourth year medical students are spending four weeks learning how to put their medical training into practice when definitive care is over one hour away.
As one of the expedition leaders for the five-day wilderness expedition component of the elective, I joined the group in the third week of their four week class, primarily working with the students to teach them how to prepare for an expedition and assisting them in packing their personal gear, their group’s food, planning their travel schedule, and learning how to canoe. It was clear that the group had bonded even more than the shared experience that medical school provides. I was interested to see how they would transfer their level of trust and support built in an intense professional environment to one that required them to mix personal and professional in the casually intense environment provided by the rivers of the Mobile-Tensaw Delta.
One of the best transformations I saw take place during the expedition was watching the group transition from being solely patient focused to wisely using resources that promoted both patient care and group well-being. Acknowledging that, if not taken care of, group members, including those providing medical care, can quickly become additional patients, the medical elective students learned and practiced the necessary skills to be comfortable for extended periods in a wilderness environment. The skills included meeting personal needs such as applying sunscreen, drinking water and making sure that personal systems were maintained. Learning to manage self-care and oversee the critical personal needs of others during medical incidents proved to have a steep learning curve, but one where learnings were quickly applied. After developing and practicing their field systems for five days, their learning culminated in the field care and lengthy canoe evacuation of a “patient” with a head injury. The sense of calm, confidence and competence they portrayed throughout the five hour process was that of experienced expedition doctors. Watching their response to the scenario, listening to their ideas and communication of plans, as well as their professional and compassionate treatment of their “patient” solidified my confidence in their ability to respond to emergencies large and small in the wilderness.
The wilderness medicine elective is designed to meet the needs of medical professionals who are interested in practicing medicine in remote environments, who wish to be expedition medical staff or to serve as medical directors for wilderness organizations. What that description fails to capture is the involved nature of improvisation, group care, personal care and environment management, all challenges that the students who participated in the LWM Wilderness Medicine Elective can attest to.
At this point, the medical elective participants have officially completed medical school, have walked across the stage, received their diplomas and are headed towards their residency placements. We wish them the best of luck in their upcoming adventures.
-Katie Cartier, LWM Program Manager
In order to safely spend time in remote locations, it is necessary for preparations to include appropriate medical training and the creation of a first aid kit with supplies to assist in the case of an emergency. It is important to know how to design a kit that meets the needs of each individual or group and to understand that there is not one perfect kit for all travel. In order to create a first aid kit that meets the needs of each trip you take, LWM encourages you to consider the following:
The practice of wilderness medicine teaches improvisation, but there are a few items that are hard to improvise effectively. Emergency response can place you in a situation where you come in contact with body substances such as blood, vomit, feces and urine. Body substance isolation (BSI) is the practice of protecting your exposure from these substances to limit the risk of disease transmission. Non-latex gloves and a CPR mask should be considered mandatory items for even the smallest first aid kit.
First aid kits are not “buy it and forget it” purchases. Items get used, wet, hot, cold, expire, and dirty due to all of the places that you take your kit. Ensure that you have the appropriate items available when you need them by periodically inventorying your first aid kit and restocking items that are used, worn out, or expired.
Acquiring a kit
The simplest way to get your first medical kit is to purchase a commercially made kit from an outdoor retailer. Commercially designed kits use names or numbers to indicated the kit’s intended use. Purchasing a pre-made commercial kit allows the purchaser to get most of the necessary items along with a carrying case without having to purchase full boxes of many of the items for the kit. As you look at which kit to purchase and maintain, ask yourself the following questions:
Who are you traveling with?
Do you travel with groups, adults, kids or solo? The more people you travel with the more opportunities present themselves to use the items in your kit. With group travel, consider adding additional reserves of commonly used items such as adhesive bandages and pain relievers. For expeditions with adults at risk for heart conditions, ensure that aspirin is in the kit. Additionally, you may consider adding a dental kit with temporary filling for adults with a history of tooth issues. If kids are on the trip, small items like bandages with cartoon characters or a small toy can go a long way to decrease their stress.
How long will you be out?
Ensure that you have an inventory that matches the length of your trip . For longer trips, increase the number of common use items such as bandages, athletic tape, non-latex gloves and over-the-counter medications. The number of these items can be decreased on short day trips. On day trips to remote environments, consider bringing an emergency blanket in the case that injury lengthens your trip resulting in an unexpected overnight.
What type of activity are you doing?
The items carried in a first aid kit should match the potential illnesses or injuries that are associated with the activity. Hikers commonly experience blisters and musculoskeletal injuries, making it beneficial to have kit including bandages, mole foam, an elastic wrap and pain relievers. A nail clipper in a first aid kit can also can reduce many potential foot issues when on trail runs, day hikes, or backpacking trips. Boaters can add a small container of high strength sunscreen and sunglasses to reduce the potential of sunburn from the reflection of the sun on the water if they run out of (or forget) sunscreen or loose their sunglasses.
What is your level of training?
It does not make sense to carry items in your first aid kit that you do not know how to use. If there is something in your kit you do not understand, take time to research what the item is used for and how to use it appropriately. In addition to your current understanding of medicine, consider adding knowledge to what you carry with your first aid kit.
Longleaf Wilderness Medicine courses address how to create first aid kits that will allow for response to minor and major emergencies. Check out a LWM course to develop your assessment and treatment skills for when the unexpected happens.
Understanding how our bodies create, maintain and lose heat is key to preventing hypothermia. By taking a few proactive measures to make sure that the body is able to optimize heat generation and maintenance, outdoor ventures in cool and cold climates can be safer and more comfortable.
The body produces heat by metabolizing the energy in the food we eat, making it important to remain well fed and hydrated before, during and after participating in activities in cold environments. Ensuring regular consumption of calories throughout activity as well as eating meals with a balance of carbohydrates, fats and proteins will provide adequate energy to keep the internal furnace burning. Proper hydration supports consistent blood volume and regular circulation of blood throughout the body and ensures that this warmth travels to the extremities and skin.
In order to retain the heat generated by the body, it is important to wear proper clothing for the environment. Using a layering system that includes nonrestrictive, dry materials will allow for a clothing system that can be adjusted throughout the activity depending on the conditions and level of exertion. The goal is to stay warm without sweating in order to avoid the resulting chill of evaporative cooling. Individuals should add and remove layers consistently to achieve warmth without sweating.
Recognizing the symptoms
Mild hypothermia occurs when the core body temperature decreases. Individuals experiencing mild hypothermia can present with signs that include violent shivering, pale, cool skin and a series of changes often referred to as the “umbles”: stumbles, grumbles, mumbles, and fumbles. Early recognition of these symptoms in ourselves and our group members is key to treating hypothermia in its mild phase.
A patient with mild hypothermia can be treated as follows:
All LWM courses provide detailed information on the body’s response to cold and cold injuries.