Cold Stress – Working outdoors in the cold weather

Four factors contribute to cold stress:

  • cold temperatures
  • high or cold wind
  • dampness
  • cold water

A cold environment forces the body to work harder to maintain its core temperature of 98.6­°F.  Cold air, water, and snow all draw heat from the body.  When in a cold environment, most of your body’s energy is used to keep your internal temperature warm.  Over time, your body will begin to shift blood flow from extremities (hands, feet, arms, and legs) and outer skin to the core (chest and abdomen).  Two common cold stress conditions are hypothermia and frost bite.


Hypothermia is a medical emergency that occurs when the body loses heat faster than it can produce heat, causing a dangerously low body temperature.  Normal body temperature is around 98.6°F (37°C).  Hypothermia occurs as your body temperature falls below 95°F (35°C).

Signs & Symptoms

  • Shivering cold stress- hypothermia signs
  • Slurred speech or mumbling
  • Slow, shallow breathing
  • Weak pulse
  • Clumsiness or lack of coordination
  • Drowsiness or very low energy
  • Confusion or memory loss
  • Loss of consciousness

Someone with hypothermia usually isn’t aware of his or her condition because the symptoms often begin gradually.  Also, the confused thinking associated with hypothermia prevents self-awareness.  The confused thinking can also lead to risk-taking behavior.


For mild hypothermia, move to a warm area and remove wet clothing.  Drink warm (not hot) sugary beverages such as sports drinks.  Avoid caffeine and alcohol.  For moderate to severe hypothermia seek medical assistance.  While waiting for emergency help to arrive, gently move the person inside if possible.  Jarring movements can trigger dangerous irregular heartbeats.  Carefully remove his or her wet clothing, replacing it with warm, dry coats or blankets covering all extremities.

Frost Bite

Frost bite is an injury caused by freezing of the skin and underlying tissues.  Frost bite is most common on the fingers, toes, nose, ears, cheeks and chin.  Exposed skin in cold, windy weather is most vulnerable to frost bite.  However frost bite can occur on skin covered by gloves or other clothing.


  • At first, cold skin and prickling feelingcold stress - frostbite stages
  • Numbness
  • Red, white, bluish-white or grayish-yellow skin
  • Hard or waxy-looking skin
  • Clumsiness due to joint and muscle stiffness
  • Blistering after rewarming, in severe cases


Mild cases can be treated with gradual warming.  Severe cases require medical care to prevent complications.  Resist the urge to place cold hands or feet in a tub of hot water.  Instead, soak the affected hands and feet in warm water (104°F to 107°F), or place a washcloth with warm water on the affected area that can’t be submerged, like nose and ears, for at least 30 minutes.  Your skin should start to heal quickly.  As it thaws, it may get red.  You may also feel painful stinging or prickling sensations, like “pins and needles.”  If uncertain of the severity, seek medical assistance immediately.

Prevention of Cold Stress

  • Wear at least three layers of clothing: the base layer with moisture wicking properties to draw the sweat away from your body; the second layer should be made of breathable material that will help to insulate the body such as fleece; and the outermost windproof and waterproof layer to offer protection from the elements.
  • Wear a hat such as a good knit cap or a ski mask.
  • Wear insulated boots or other footwear sized appropriately.  Tight-fitting footwear restricts blood flow, as can wearing too many socks.
  • Wear insulated gloves sized appropriately, especially when contacting metallic surfaces and tool handles.
  • If you get hot while working, open your jacket, but keep hats and gloves on.
  • Keep a change of dry clothing available in case work clothes become wet.
  • Use the buddy system and try to work in pairs to keep an eye on each other and watch for signs of cold stress.
  • Avoid alcohol, certain medications and smoking.

Disclaimer: This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment.  Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.