As we enter the spring in the Northwest, getting out in the longer light and warming temps is a natural draw. We still have several months of precipitation ahead though, and wetness and wind combine to cause heat loss which makes hypothermia a common concern for outdoors people this time of year.
Hypothermia can be a fairly common condition for back country travelers. Mild hypothermia is a discomfort, but is dangerous because it can progress rapidly. Left untreated it can lead to shock, becoming fatal. It’s important to know how to prevent hypothermia, how to identify when someone is hypothermic, and how to treat them.
As a mountain guide, I focused most of my efforts attacking hypothermia in the preventative stage. Like dehydration, it’s much easier to not allow hypothermia to happen, or to catch it early. If someone in your group has serious hypothermia, it’s a true “stop and fix” situation. Unfortunately your group may be either unprepared to manage a hypothermic patient, or in doing so you are putting more of the group at risk due to extended exposure to the same conditions (picture a group huddled around a team member in the cold rain, on a windy mountain ridge as the sun is setting…). To understand prevention, it’s best to know what causes hypothermia:
- Inadequate protection from exposure
- Lack of proper hydration and nutrition
- Lack of proper planning for the activity or conditions
When you’re out exercising in cool weather, if the exercise rate is high and breaks are short, the body will keep itself warm, provided it has enough fuel and water. But down time due to unexpected delays, extended time out due to conditions or human factors, and lack of extra food and clothing from light packing are common situations that heighten risk of exposure. Often hypothermia is a secondary by product of a separate issue, such as attending to a minor injury, adjusting or fixing gear.
Prevention of Hypothermia:
- Look at the weather forecast and plan accordingly. Regardless of forecast, if you will be in mountainous terrain having extra clothing, food, and water is always a good idea. I always carry a lightweight bivy sack as well. It takes up little space, and can be a lifesaver.
- Hydration and nutrition. Have extra snacks and water, and keep them handy. Gels and energy bars are great options that don’t take up much space and can be stored for the next time out if you don’t use them. If you are out with partners, make sure that they are taking care of themselves as well.
- Proper clothing. “Cotton kills:” layering with synthetic or wool garments, packing a fleece hat and gloves, and waterproof shell are basic starting points.
- Proper layering en route. Know how and when to make adjustments to your clothing (zipping up/down, adding and removing layers or garments).
- Good rest management. Pick rest stops that are sheltered, encourage eating and hydration at each stop, and keep break times limited when conditions are cool/cold and/or wet. When picking rest times/spots, always take into account other team members/partners. No one wants to look like they are holding up the group, but it’s up to all team members to keep an eye on each other and work together.
- Avoid sweating if possible by finding a steady, reasonable pace for the group.
- If you are going to be out for extended times in cooler/colder temps or conditions, consider bringing a small thermos with a hot drink. It’s amazing what a difference it can make when you getting chilly, as it warms you from the core.
So now we have some baseline practices that will help us to avoid exposure or risk. But despite good planning, sometimes best intentions don’t pan out. Or you may come across a hiker from another party who you may suspect is in trouble. What are the signs to look for?
Signs and Symptoms: Mild Hypothermia
- Shivering
- Patient exhibits the “Umbles”: stumbles, mumbles, grumbles, fumbles
- Changes in personality. Often someone who is normally talkative or friendly can become quiet or cranky, an early sign
- Body temperature: lower than normal, but usually above 90-92 degrees f.
- Pale, cool skin
Signs and Symptoms: Severe Hypothermia
- Body temperature below 90 degrees f. (you can purchase a hypothermia thermometer for your med kit made specifically to read lower ranges)
- Patient is no longer shivering, severe lack of coordination
- Incoherence
- Weak, slow pulse
- Paradoxical undressing. There have been a couple of high profile events in the Northwest in the last few years which involved hypothermic patients leaving clothing and layers about. The media initially inaccurately reported that they might be leaving a trail for rescuers to follow; in fact they were in the late stages of hypothermia.
Treatment: Mild Hypothermia
- Get out of areas of exposure- gain shelter while making adjustments
- Add additional layers to the patient, including insulating layers
- Replace wet base layers with dry ones
- Short-term exercise to generate heat: jog in place, quick calisthenics
- Treat patient for dehydration and ensure that adequate energy is on board
- Ingest warm, sweetened liquids if possible
- Light a fire (if feasible) or stove for heat
- Place patient in sleeping bag, making sure the are well insulated from the ground
- Monitor patient if condition worsens or does not improve. Do not leave a hypothermic patient alone
Treatment: Severe Hypothermia
- A severely hypothermic patient is in a critical situation. Due to the potential for ventricular fibrillation, the patient must be handled and treated very carefully.
- The best treatment involves protection from the elements, and re-warming on the spot
- Shelter the patient and the rest of the group to allow you to give treatment while not endangering others.
- Replace wet clothing with dry garments, make a “hypo wrap” consisting of one or more sleeping bags with a bivy sack or hypothermia blanket (essentially a large space blanket) around the outside, and thorough insulation from the ground.
- Add heat inside the wrap by placing well-sealed water bottles containing very warm water, heating pads, or other safe heat sources around the patient, ideally in the groin and armpit areas. Body-to-body contact is also an option; though monitor the rescuer for heat loss as well.
- If evac is required, either dispatch a team member with coordinates for rescue to alert rangers, SAR or other authorities. If self-rescue by the group is the best option, proceed slowly and smoothly to avoid jarring patient which, may result in ventricular fibrillation.
As is often the case, proper planning and prevention are keys to avoiding hypothermia. While en route, monitoring yourself and your party and making the proper adjustments at the correct times is an important skill that is gained with experience. Lastly, knowing how to identify and treat hypothermia is your last line of defense, so make sure that you and members of your party have appropriate training and kit when you plan for extended sessions in the hills.
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