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Prepare for and Recognize Hypothermia
Hypothermia can pose a severe problem in the wilderness and, without proper preparation and recognition, could be fatal. That is why knowing Hypothermia prevention in the wild is important to understand. Not only can it be a primary concern on the trail, but it can also compound initial complications and make a situation worse. However, planning, noticing the signs, and responding efficiently can save a great deal of trouble for a party.
Hypothermia occurs when the body temperature drops below 35°C (95°F). At this point, the body will initiate its mechanisms to combat hypothermia onset. For example, someone will start shivering along with their blood vessels at the skin, and extremities will constrict to draw the blood into the core, preserving heat. When the core body temperature is 32-35°C (90-95°F), a person will present the symptoms of mild hypothermia listed below:
- Pale appearance from vasoconstriction
- Uncontrolled shivering
- Potentially altered mental status
- Poor judgment, confusion, disorientation
- Increased urinary frequency
- Fine motor skill loss
- Tachycardia, hypertension, and tachypnea
Vasoconstriction and shivering expend significant energy; if that energy supply is not replaced, these mechanisms will fail. To address this, they need substance to replenish their energy. High-carbohydrate liquids and food are ideal as they will provide long-lasting energy. If there is an option to remove them from the cold, get them into a room-temperature location.
Moderate Stage Hypothermia
If a person does not take mitigation measures and their energy depletes, they will soon enter into moderate hypothermia 28-32°C (82-90°F), which presents these symptoms:
- Decreased level of consciousness
- Slurred speech
- Dilated pupils
- Decreased Vital Signs
- Muscle rigidity without shivering
- Possible cardiac dysrhythmias
When defenses are weakened, the condition will deteriorate. A sign that hypothermia is getting serious is when they display an altered mental status. Take action when you notice them acting funny or disoriented. Active rewarming is required, where heat needs to be applied to the head, neck, chest, back, armpits, and groin. Skin-to-skin contact is an excellent method to achieve this; if a sleeping bag is available, climb into a sleeping bag with them to warm them up. Evacuation for this person is imperative, as they cannot rewarm themselves once they have reached moderate hypothermia.
Severe Stage Hypothermia
If their condition progresses further, they will enter severe hypothermia 24°C – 28°C (75 – 82°F), displaying any number of these symptoms:
- Comatose with fixed dilated pupils
- Muscular rigidity
- Nearly undetectable blood pressure
- Apnea with severe bradycardia
- Cold and cyanotic skin
- Prone to cardiac dysrhythmias
As energy is lost, peripheral vasodilation is expected, and the warm blood from the core will travel to the skin and extremities, making them feel warm. Compounded with a relentless altered mental status, this may lead to paradoxical undressing. This is why it is sometimes reported that people with hypothermia take all of their clothes off and run into the cold.
Continue actively rewarming and, if possible, provide them warm fluids via an IV.
Handle the patient gently because their cardiac output is irritable and could easily be disrupted.. For this reason, slowly rewarming the person is necessary. If thrown into an intense heat source quickly, they could go into shock or cardiac arrest. Evacuation with active rewarming should be the primary goal. Consider evacuation to a center capable of initiating cardiopulmonary bypass (CPB)/ECMO).
If an individual’s symptoms progress further, then they will enter profound hypothermia 24°C (75°F):
- Significantly low rate of survival
- Vital signs not present
- High likelihood of cardiac arrest
Profound hypothermia is a severely critical state that one should never reach if proper planning and mitigation have taken place. Putting the work in ahead of time to properly plan will avoid hypothermia from reaching a serious point like this.
The best way to combat hypothermia is by making sure it does not happen in the first place. Have a solid plan of the activity, how long it may take, and what to do in the case of an emergency. Also, take into consideration each member’s ability levels and equipment. Children, the Elderly, and those with medical conditions may be more prone to hypothermia.
When planning for Hypothermia prevention in the wild, consider injuries, illnesses, or intoxicants such as alcohol speed up the onset of hypothermia. So consider those factors when planning. Ensure that everyone in the party is dressed appropriately for whatever activity they are doing will keep their core body temperature regulated. Consider bringing backup gear in case someone gets cold or wet, and needs to change.
Finally, bring plenty of food to keep everyone’s energy levels maintained throughout the activity.
Remember that it does not have to be cold for hypothermia to develop, so planning and preparing for the trip is essential. Getting lost in the wilderness is a recipe for hypothermia; if a party loses track of where they are, they may be out much longer than expected. Mapping out the route and noting potential opportunities for wrong turns could avoid a serious situation.
Hypothermia Considerations When Providing Care
If a medical emergency happens in the wilderness, giving someone care and evacuating them to a medical center can take quite a while. Throughout this procedure, a patient is exposed to the elements, and if not managed, they will be impacted. If it is cold, windy, or wet, a person remaining stationary could quickly develop hypothermia. While focusing on the primary issue, minimizing their exposure to the elements will be crucial. If they are lying on the snow, create a barrier between them and the snow; if it is windy or precipitating, find a way to get them out of the weather. Some conditions, such as shock or burns, put a person at a higher risk of developing hypothermia. Taking the necessary measures will lower the onset and severity of these symptoms.
Hypothermia and CPR
When a person is experiencing severe hypothermia, it can be very challenging to find a pulse or other signs for life, so it is best to check vitals for up to a minute before moving forward. If the core body temperature is less than 30°C, rewarming may be required before establishing a regular heart rhythm. When an AED is present, attach it to the individual to obtain a reading and potentially deliver a shock. If the heart is in ventricular fibrillation, begin delivering shocks as prompted. If the heart is still in Ventricular Fibrillation after three shocks, then pause the shocks.
A person exposed to the cold will have their basal metabolic rate decreased and may have prolonged survival without a detectable heart rhythm. If a patient is found that is perceived dead, before attempting CPR on them, get them out of the cold to warm them. This may be enough to restart their body and bring them back to a perfusing heart rhythm. If already warmed, and are thier body is still cold, they are most likely dead. It may not be possible to bring them back at that point.
Once hypothermia progresses past mild to moderate, it becomes significantly more challenging to treat. Preparing for exposure and recognizing early signs of onset is the best way to combat hypothermia. Additional resources or an evacuation plan before leaving will be invaluable in emergencies. Take the time before venturing into the elements to minimize the risk and prepare a procedure to be used in case of an emergency.
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National Association of Search and Rescue. ENVIRONMENTAL EMERGENCIES. Accessed 9 Jan. 2023.
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Roy, Adam. “How to Prevent, Recognize, and Treat Hypothermia.” How to Prevent, Recognize, and Treat Hypothermia, Backpacker Magazine, 21 Feb. 2021, https://www.backpacker.com/skills/outdoor-first-aid/hypothermia-101/.