It’s much easier to just keep an eye out for the symptoms of hypothermia and to take some simple precautions to help keep you safe and coherent when temperatures begin to fall.

Marine Corps Order 3470.1A provides guidance on preventing cold-weather injuries, particularly hypothermia and frostbite. Although you can find similar information from a multitude of sources like the Mayo Clinic and the Center for Disease Control, my penchant for the Naval letter format and the fact that I keep this order, along with a number of others, in a binder in my office helps me retain the necessary wave tops I need to keep my pants intact and on my body during cold-weather activities.

Those nurses aren’t going to get another free show out of me, nor will they from you if you follow these simple guidelines:

Preventing frostbite

Frostbite, as the Marine Corps defines it, is damage caused by the “crystallization of tissue water in the skin and adjacent tissues.” In layman’s terms, frostbite is caused when the water inside your skin and near-surface tissues freezes. Skin exposure at sub-freezing temperatures can cause frostbite anywhere on your body, but the regions that are most commonly susceptible are your hands, feet, and face.

Frostbite can get tricky because ambient temperatures don’t need to be below freezing for the early stages of the condition to set in. Wind chill can easily bring otherwise sustainable temperatures to below freezing, and as day wears into night, frostbite may set in even faster after prolonged exposure to near-freezing temperatures.

The symptoms of the early stages of frostbite are pretty common: an uncomfortable cold sensation followed by numbness. As the condition worsens, your skin will turn red before transitioning to gray or white; and any fingers or toes affected by frostbite may feel overly stiff or wooden. Eventually, frostbitten parts of your body will turn black due to a lack of blood flow, and they may sometimes even fall off.

The prevention and treatment of frostbite can be broken down into three steps:

1. Use the buddy system. Because the early stages of frostbite can occur with fairly little exposure, many of us tend to ignore them for a time. We get focused on what we’re doing, or we don’t want to acknowledge the nuisance presented by our cold hands or feet, so we choose to wait a bit longer before heading back inside or swapping out our gear. This is where your buddy comes in. Ensure your buddy understands that it’s his or her responsibility to keep you from being an idiot, and vice versa. Being responsible for the wellbeing of one another may sound inconvenient, but it encourages a higher level of awareness than we usually exercise for ourselves. Your concern for the condition of your friend will force you both to acknowledge when one or both of you need to address a potential frostbite situation.
2. Carry spare gloves, socks and footwear whenever possible. So much of cold-weather preparation comes down to having the right gear; but sometimes, simply having it isn’t enough. Sweat, melting snow or exposure to water can all compromise even the warmest of gloves and boots. If you find your hands or feet wet, immediately change out the wet gear for dry replacements.
3. Never attempt to treat frostbite in the field if you can avoid it. If you believe frostbite is beginning to set in, you may be tempted to try to thaw the affected region of your body before setting out for home. This is actually quite dangerous, as the damage frostbite does to your soft tissues can be exacerbated by the partial thawing and refreezing of the moisture found within them. Instead, double-time it back to camp where you can appropriately warm yourself back up.

Preventing hypothermia

Unlike frostbite, hypothermia affects your entire body. As it progresses, your ability to reason and make sound decisions may also be compromised. As my trusty Marine Corps order points out, “even mild hypothermia can render personnel ineffective.”

Hypothermia sets in when your body’s core temperature dips below 95 degrees Fahrenheit and is unable to produce heat faster than heat is escaping your body. Wind chill must also be taken into account for hypothermia, and it’s important to note that you can succumb to hypothermia even in non-freezing conditions.

The symptoms of hypothermia can be difficult to pinpoint, as they often manifest simply as tiredness. Feeling abnormally weak or fatigued and having bouts of confusion is common among those suffering from the early stages of hypothermia. This can significantly compromise an individual’s ability to get themselves out of the dangerous situation or to articulate their symptoms. If a person that has been shivering suddenly stops doing so, they are likely entering the more advanced stages of hypothermia. Dizziness and nausea are also common in hypothermia patients.

As soon as you recognize the symptoms of hypothermia in yourself or your buddy, it’s imperative that you take immediate action to stop the loss of heat from the body. If left untreated, hypothermia will leave you or your hiking partner utterly incapacitated, and if you’re not as lucky as me, you’ll die soon thereafter.

Preventing hypothermia from setting in also demands that you travel with a buddy, but here are a few more tips to help ensure that you maintain a safe body temperature in a winter wonderland:

1. Dress in layers. It’s always better to wear more layers than necessary, then remove them in order to regulate your body temperature. Choose wool or other wicking materials, rather than cotton, as cotton will expel heat from the surface of your skin if it gets wet. Base your clothing choices on your level of activity, and keep your layers baggy to capture pockets of air between them.
2. Try not to sweat. While working outdoors, your body temperature will increase and, if you’re not careful, you may find yourself working up a good sweat. That sweat will make it incredible difficult to maintain a safe body temperature once your activity level slows down again. Remove layers of clothing and stay conscious of your pace in order to maintain a moderate body temperature while working or hiking outdoors.
3. Stay as dry as possible. Just like sweat, any kind of fluid can drain your body’s warmth. Falling in a river, spilling a drum of fuel or just tripping into a puddle can kill you in a field environment if you don’t have a change of clothes and the means to get warm. If you find yourself wet, change immediately if possible, and seek shelter and warmth. If need be, build a fire where you are until your clothing is dry once again.

Hypothermia and frostbite aren’t the only risks for holiday hikers, but taking action to prevent these two common dangers can go a long way in ensuring that you make it to Christmas.

Remember to always hydrate before taking treks into the great unknown; and, in addition to your efforts to prevent cold-weather injuries, exercise the same cautionary methods that you use during warm-weather hikes.

And don’t forget your buddy. They just might save your life.