Cold Weather Safety
When you are outdoors during the colder months and during rainy days, it is important to know the difference between hypothermia, frostbite, frost nip and tench foot. As well as how to prevent and when to seek help.
Hypothermia is a medical emergency that occurs when the body’s temperature drops to a level that inhibits proper function- when the body’s core temperature is below 98.6 degrees Fahrenheit.
Signs and stages:
- The beginning signs of hypothermia
- 'the umbles': mumbling, bumbling, stumbling, & fumbling
- slurred speech
- lack of fine motor skills
- unclear or inconsistent thoughts and conversation
- Moderate hypothermia - the body’s temperature drops below 95 degrees
- Dazed consciousness
- loss of motor coordination
- slurred speech
- violent shivering
- irrational behavior
- paradoxical undressing, a person starts to take off clothing, unaware that they are very cold.
- Severe hypothermia- the body’s temperature drops below 92 degrees.
- shivering in waves – violent, uncontrollable shaking interrupted by calm pauses that increase in duration until shivering finally ceases
- Victims might fall to the ground, incapable of walking, and curl up into a fetal position to conserve heat.
- muscles contact
- skin becomes pale
- pupils dilate
- heart rate decreases
- At 90 degrees, the body shuts down all peripheral blood flow and reduces breathing and heart rate, in an attempt to keep the body alive at all costs.
- At 86 degrees, the body is in a "metabolic icebox," where the person looks dead but is still alive and able to be saved with professional medical care.
- As hypothermia develops, it becomes increasingly difficult to raise the individual's temperature to 98.6 degrees F. The key to fighting hypothermia is prevention, these include:
- staying hydrated
- Keeping hydrated allowed the body to preform properly and stay warm. Dehydration leads to a decrease in body temperature and reduce mental clarity.
- staying dry
- Never allow your clothing to become wet from sweat, water, or snow. Water causes hypothermia 25 times faster than the cold air.
- correct clothing material
- Do not wear cotton when recreating outside, cotton absorbs water easily which makes it loose its insulating properties.
- wear synthetic clothing or merino wool and always bring a shell layer to shed water and snow.
- layering clothing
- Layers help manage heat loss and cut down on sweat
- increasing your ability to change your clothing to match your heat output.
- Large amounts of heat can also be lost through the exchange of heat between to objects in contact, like your hand on a cold snow shovel handle.
Frostbite can occur within seconds in extreme cold or windy conditions in one of two stages: superficial frostbite & deep frostbite.
- the freezing of all the layers of skin
- appears white, with no sensation and the skin feels soft and slushy
- the freezing of muscle and even bone in extreme cases
- appears white, without sensation but the skin feels hard and waxy to the touch.
Rewarming the area and the effects of frostbite:
- soak the affected area in warm water, NOT hot water! Additional damage to the area will occur if hot water is used.
- loss of limbs may occur in extreme cases.
- while the numbing sensation may go away, intense pain can occur
- it is normal for the victim to vomit or faint from the pain
- If a person acquires frostbite on their foot, it is important to consider when the appendage should be rewarmed, especially in the back country. Once the foot is rewarmed, travel will be impossible.
- If a victim has both hypothermia and frostbite, increasing the core body temperature should always be a priority over rewarming the frostbitten area.
A very mild version of frostbite where freezing of the top most layer of skin occurs. Frost nip commonly occurs on the nose, cheeks, ears, fingers and toes.
- Generally easy to reverse
- rewarming the affected area by placing it on another persons warm skin or by covering it up with a face mask, hat or glove.
- The skin will appear white and sensation may or may not be present
Afterwards, the skin may become very dry or blister. Often times the area will become prone to future cases of frost nip and frostbite. Do not rub frost nip, the ice crystals within the skin can cause damage when moved.
Also called immersion foot, occurs when the foot is exposed to wet conditions for extended periods of time which can occur any time of the year in Alaska
Signs of trench foot include:
the skin becomes pale and mottled, or even dark purple, grey, or blue, as the affected tissue generally dies.
six hours of trench foot, permanent tissue damage can happen
twenty-four hours, the appendage may be lost.
Once trench foot occurs, the circulatory damage may may be irreversible and the individual may be more prone to trench foot in the future.
picking your shoes while in water:
- neoprene-lined rubber boots
- do not let the foot breathe and hold moisture inside the boot.
- Waterproof hiking boots are often useless
- once water gets into the boot, it is held inside
- Trail running shoes might be a good choice for some activities but many are not waterproof at all and also may not provide enough support for traveling over difficult terrain.
- take time to allow wet feet to dry
- if you are camping use sleeping socks at night, which stay in your sleeping bag.
- As soon as you get into your sleeping bag, put them on and enjoy a night of dry, warm feet!