Just as there is the potential for heat stress in spring and summer, there is the potential for cold stress in the fall and winter months. Cold stress happens when the skin temperature drops and eventually reduces the internal body temperature. When the body is unable to warm itself, serious cold-related illnesses and injuries may occur, and permanent tissue damage or death may result. The body loses heat through:

  • Convection – We can lose up to 10-15% of our body heat as air moves across the skin’s surface.
  • Radiation – The body radiates and loses heat. Your body loses 40-45% of its heat through the head and neck. Combine that with wrists and ankles, and heat loss approaches 60%.
  • Conduction – Holding cold tools or kneeling or sitting on the cold ground will cause your body to lose heat.
  • Respiration – When we breathe, we warm the air in our lungs. Then we exhale that warm air, resulting in significant heat loss. Breathing through your nose helps warm the air as it enters your body slightly more than breathing through your mouth.


It is important to dress in light layers that you can add/remove as you become colder or warmer. Excessive layers can cause you to sweat, leading to wet clothing that can affect your body’s ability to maintain its temperature. Wear synthetic or cotton/synthetic blends as a base layer next to your skin to wick away sweat.


People who take certain medications, are in poor physical condition or suffer from illnesses such as diabetes, hypertension or cardiovascular disease may be at increased risk during cold weather exposure.

Cold stress often causes the body to release survival hormones such as adrenalin and cortisol. These cause the liver to release more glucose for energy, which can result in higher-than-normal blood sugar levels. Cold weather can also increase blood pressure, resulting in the increased potential for heart attacks.


  • Dress in layers and cover your head and hands.
  • Keep extra gloves, hats and jackets available. This enables you to add layers or replace wet clothing.
  • Take frequent breaks in a warm, dry area to limit the effects of exposure to the cold.
  • Include a thermometer and chemical hot packs in your first aid kit.
  • If someone shows signs of cold-related stress or injuries, get them to warmth immediately.

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It is important to recognize how winter weather can affect working conditions and produce cold weather-related hazards resulting in an injury.


Hypothermia is brought on by extended exposure to very cold temperatures. When your body loses heat faster than it can produce it, your temperature can drop to abnormally low levels. This lowered body temperature can affect your brain and your ability to think clearly or move well.

What makes hypothermia especially dangerous is that a person may not know it’s happening and won’t be able to do anything about it.

Severe hypothermia can cause an irregular heartbeat leading to heart failure and death.


  • Shivering.
  • Exhaustion.
  • Confusion.
  • Fumbling hands.
  • Memory loss.
  • Slurred speech.
  • Drowsiness.


  • Move the person into a warm room or shelter.
  • Remove wet clothing.
  • Warm the center of the person’s body (chest, neck, head and groin).
  • Encourage the person to drink something warm.
  • Find medical help as soon as possible.

Download a printable PDF and recording form here.

Members can download the audio version of this toolbox talk here.


Working in the cold winter weather can be like working in the extreme heat:

  • You must be prepared for it.
  • You must be equipped for it.
  • You must get acclimated to it.

Employees who work in the cold weather during the winter months can be at risk of cold stress and injuries. It’s important to recognize cold weather hazards and potential for injury.


  • Workers taking certain medications, who are in poor physical condition or suffer from illnesses such as diabetes, hypertension or cardiovascular disease may be at increased risk during cold weather exposure.
  • Dress in layers that can be added and removed as you get warmer or colder. Sweating from too many layers can cause clothing to become wet. Overdressing can also restrict your movement and increase the potential of an accident.
  • Wear synthetic or cotton clothing next to the skin to wick away sweat.
  • Hands and head should always be covered to minimize heat loss.
  • Take frequent breaks in a warm, dry area to limit the effects of exposure to cold temperatures.


  • Trench foot is caused from prolonged exposure to wet and cold conditions. Wet feet lose heat 25 times faster than dry feet. To prevent heat loss, the body constricts blood vessels to shut down circulation in the feet. Skin tissue begins to die due to lack of oxygen and nutrients.
  • Hypothermia is a severe condition when the body is unable to produce enough heat to counter the heat that it is losing. If your body loses heat more quickly than it can make it, your core temperature will fall. As it falls, the body shifts blood away from the skin to reduce the amount of heat that escapes.
  • Frostbite is characterized by reddened skin with gray and white patches, skin and limb numbness, firm skin and limbs and, in severe cases, blisters.

If employees show signs of cold-related stress or injuries, it’s important to get them warm and dry immediately.

Download a printable PDF and recording form here.

Members can download the audio version of this toolbox talk here.

Winter Work Safety

Each season brings its own set of hazards for construction workers. As we enter the winter season, be especially mindful of the weather, its effects on the body and proper actions to prevent serious injury, permanent tissue damage or even death.

Low temperatures, high winds, dampness and cold water can contribute to cold-related stress on your body. Wearing inadequate or wet clothing increases the effects of cold on the body. Alcohol, nicotine, caffeine and some medications inhibit the body’s response to the cold and can impair judgement.

Fatigue, nausea, confusion, lightheadedness and profuse sweating are symptoms of hypothermia. Exposed skin can start to freeze at just 28F causing frostbite. Deep frostbite can cause blood clots and even gangrene.

Following are several tips to consider while working outdoors during the winter months:

  • Keep your body temperature at or about normal (98.6F). This can be accomplished by wearing layers of clothing.
  • Wear cotton or lightweight wool fabrics next to your skin. Add layers when you are cold, remove layers when hot.
  • Keep your clothing as dry as possible. Protect your clothing as needed by wearing rain gear and other durable garments. Keep an extra pair of socks handy so you can change them as needed. You may also want to consider investing in waterproof footwear.
  • Protect your head, neck and ears. Up to 40 percent of body heat can be lost when the head is exposed.
  • Wear the right gloves for the work you are doing. They should have enough insulation to keep you warm and prevent frostbite, but thin enough so you can feel what you are doing if you are manipulating controls or tools.
  • Keep your safety eyewear from fogging up in the cold. Use anti-fog coatings and wipes that are appropriate for your eyewear.

If your skin becomes discolored and it appears that circulation has been limited, then you are probably experiencing the early stages of frostbite. If this occurs, find a way to immediately start warming that particular part of the body. Tips for treating frostbite include:

  • When possible, go indoors or to a warmer area to prevent further exposure.
  • Never rub or massage the affected body part.
  • Never use hot water. You should gradually warm the frostbitten area by immersing it in lukewarm water.
  • If blisters develop, cover them with a bandage or gauze to prevent them from opening and becoming infected.
  • Refrain from smoking as it slows down the circulation of blood to the extremities.
  • Avoid caffeine. It constricts blood vessels.
  • When normal feeling, movement and skin color have returned, the area affected should be dried and wrapped to keep it warm.
  • If the condition does not improve, seek professional medical attention.

Taking preventive action is your best defense against having to deal with extreme cold-weather conditions. Prepare in advance, observe safety precautions and reduce your risk of weather-related injury.

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