Cold Weather Injuries

November has arrived, as well as the first snowfall in Alberta. We know, it’s early and it’s still officially fall. However, it’s never too soon to start thinking about the inevitable cold weather we will be experiencing in the coming months. So, today, we want to discuss cold weather injuries.  

Cold weather may cool body parts resulting in various cold injuries. Non-freezing cold injuries include chilblains, immersion foot, and trench foot. Freezing injuries include windburn, frostnip, frostbite, and hypothermia. 

The toes, fingers, ears, and nose are at greatest risk because these areas do not have major muscles to produce heat. The body preserves heat by keeping the internal organs warm, thus reducing blood flow to the extremities under cold conditions. In addition, hands and feet tend to get cold more quickly than the body because: 

• they lose heat more rapidly since they have a higher surface area-to-volume ratio. 
• they are more likely to be in contact with colder surfaces than other body parts.

If the eyes are not protected with goggles in high wind chill conditions, the corneas of the eyes may freeze. 

 
Types of Cold Weather Injuries 

Chilblains  

These mild cold injuries are caused by prolonged and repeated exposure for several hours to cold air temperatures, but not freezing (from above freezing (0°C or 32°F) to as high as 16°C (or about 60°F)). In the affected skin area, there will be redness, swelling, tingling, blisters, and pain. Seek medical help if an infection occurs. Chilblains will usually resolve on their own, especially in warmer weather. Recurrence may occur. 

Immersion foot 

This occurs in individuals whose feet have been wet, but not cold, for hours, days or weeks. It can occur at temperatures up to 10°C (50°F). The primary injury is to nerve and muscle tissue. Symptoms include tingling and numbness; itching, pain, and swelling of the legs, feet, or hands; or blisters may develop. The skin may be red initially and turn blue or purple as the injury progresses. In severe cases, gangrene may develop. 

Trench foot  

Trench foot is a "wet cold disease" resulting from prolonged exposure in a damp or wet environment from above the freezing point to about ten (50°F). Depending on the temperature, the onset of symptoms may range from several hours to many days, but the average is three days. Trench foot is more likely to occur at lower temperatures, whereas an immersion foot is more likely at higher temperatures and longer exposure times. A similar condition of the hands can occur if a person wears wet gloves for a prolonged period under the cold conditions described above. Symptoms are like an immersion foot.

Windburn  

This occurs when cold wind removes the top layer of oil from the skin, causing excessive dryness, redness, soreness, and itchiness. 

Frostnip  

Frostnip is the mildest form of a cold injury. It occurs when ears, noses, cheeks, fingers, or toes are exposed to the cold and the top layers of the skin freeze. The affected area's skin turns paler than the area around it, and you may feel pain or stinging, followed by numbness. The skin may also appear shiny and rosy, as well as hardened. The top layer of skin may feel hard, but the deeper tissue feels normal (soft). It is a warning that frostbite is beginning. 

Frostbite  

Frostbite is a common injury caused by exposure to cold or contact with cold objects (especially metal ones). It may also occur in normal temperatures from contact with cooled or compressed gases. The skin may look waxy and feel colder than the area around it. It may also be harder to the touch. Blood vessels may be severely and permanently damaged, and blood circulation may stop in the affected tissue. In mild cases, the symptoms include skin inflammation in patches accompanied by pain.  

In severe cases, there could be tissue damage without pain or burning or prickling sensations resulting in blisters. Frostbitten skin is highly susceptible to infection, and gangrene (local death of soft tissues due to loss of blood supply) may develop. 

Hypothermia 

In moderately cold environments, the body's core temperature does not usually fall more than 1°C to 2°C below the average 37°C because of the body's ability to adapt. However, in the intense cold, without adequate clothing, the body cannot compensate for the heat loss, and the body's core temperature starts to fall. The sensation of cold, followed by pain in exposed parts of the body, is one of the first signs of mild hypothermia. 

As the temperature drops or exposure time increases, the feeling of cold and pain starts to diminish because of increasing numbness (loss of sensation). If no pain can be felt, serious injury can occur without the victim's noticing it. Next, muscular weakness and drowsiness are experienced. Additional symptoms of hypothermia include the interruption of shivering, diminished consciousness, and dilated pupils.  

Cold stress (not hypothermic) 

• Shivering
• Normal mental status
• Able to care for self

Mild hypothermia 

• Vigorous shivering and complaining of the cold
• Decreased physical function
• Difficulty taking care of self

Moderate hypothermia 

• Weak and intermittent shivering or shivering that later stops
• Sometimes complaining of the cold
• Lack of coordination or speech; confused or unusual behaviours
• Impaired judgment
• Possible unresponsiveness

Severe hypothermia 

• Shivering stops
• Unresponsiveness; breathing slows down or stops
• Body feels stiff
• No pulse

It is imperative to be aware of cold injuries, symptoms and how to prevent these from occurring. Next week, we will discuss in further detail the ways in which you can ensure these types of injuries don’t happen and stay safe all winter long.