As with other hazards, worker education and training are crucial to preventing cold stress. By the time they complete their training, workers need to understand:

  • What cold stress is;
  • Why it’s dangerous;
  • How to protect themselves from the danger;
  • How to recognize the signs and symptoms of the different forms of cold stress; and
  • How to respond if they or a co-worker exhibits such signs or symptoms.

Here’s how to provide introductory cold stress training to your own workers.

GET THEIR ATTENTION: Start out by letting workers know what’s at stake. Explain that being in the cold too long isn’t just uncomfortable but dangerous because it can lead to a condition called cold stress, which can cause serious injury and even death.

MAKE IT REAL: Tell workers that in the U.S., about 700 people die of cold stress each year—which is   more than the number of people who die in floods and tornadoes. Explain who’s at the most risk, including:

  • Older workers—about 50% of all cold stress victims are 65 or older;
  • Workers who work outdoors, including in agriculture, construction, oil and gas extraction and utilities;
  • Workers who work in cold indoor environments, including refrigerated facilities in warehouse food plants and warehouses;
  • Workers who work near or above water, like fishermen; and
  • Divers and others who work in water.

EXPLAIN THE DANGER: Explain that human beings are warm-blooded. That means their bodies must maintain a fairly constant internal temperature to function properly. If body temperature falls too low, the blood vessels constrict, or tighten up, and it becomes harder to circulate blood throughout the body. After a while, the body shifts blood flow away from the extremities (limbs, fingers, toes, nose, etc.) and to the core (chest and abdomen). Tell workers that these effects from cold can result in a series of dangerous and potentially fatal conditions known as cold stress.

DESCRIBE THE 4 KINDS OF COLD STRESS: Explain that there are 4 forms of cold stress and describe each one:

Condition Description Potential Results
Frostbite Freezing of the extremities due to loss of blood flow Tissue damage, amputation
Trench foot (aka immersion foot) Injury to the feet caused by prolonged exposure of the feet to wet and cold which causes blood flow to shut down Tissue damage, amputation
Chilblains Exposure to cold damages blood vessels and causes ulcers or blistering of the skin Tissue damage
Hypothermia Body temperature drops so low that the body loses heat faster than it can replace it. Result: The body uses up all its stored energy and can no longer produce heat Shutdown of bodily functions and systems which can cause death

Emphasize that hypothermia is the most dangerous form of cold stress.

EXPLAIN HOW COLD STRESS HAPPENS: Tell workers that normal body temperature is 98.6° F and that the body can withstand minor and short-term fluctuations up and down. Explain that cold stress becomes a threat when core body temperature drops below 95.0° F. Let workers know that this can happen as a result of being exposed to cold air or surfaces.

EXPLAIN HOW GREAT THE RISK IS: Tell workers that the risks of cold stress are based on how cold the conditions are and how long they’re exposed to those conditions. Make sure that workers understand that to determine how cold conditions are, you must take into account not just actual temperature but other factors that affect how cold it actually feels on the skin.

EXPLAIN THE FACTORS AFFECTING RISK: List the risk factors for cold stress, including:

  • Air temperature;
  • Wind speed—air feels colder when it’s blowing around;
  • Humidity; and
  • Being in contact with cold or wet floors or surfaces.

Explain that people can withstand the cold better than others and, accordingly, that the risk of cold stress is also a function of a worker’s age, gender, condition and other physical characteristics affecting their tolerance level.

EXPLAIN YOUR PREVENTION STRATEGY: Explain that the key to preventing cold stress is to implement measures to ensure that workers aren’t exposed to conditions that cause their core body temperature to drop below the critical 95.0° F threshold. Then, describe those measures.

DESCRIBE YOUR ENGINEERING CONTROLS: Tell workers what engineering controls you use to control the work environment and how cold it feels, e.g., use of radiant heaters, barriers to block wind and/or establishment of “warm-up” centers.

DESCRIBE YOUR ADMINISTRATIVE/WORK CONTROLS: Next, explain that the second prong of the prevention strategy is to ensure that work involving exposure to cold stress is carried out as safely as possible. Then list the actual work/administrative measures that you implement, such as scheduling cold work for the warmest parts of the day, continually monitoring weather conditions while work is conducted and/or letting workers take frequent “warm-up” breaks.

EXPLAIN WHAT PROTECTIVE CLOTHING IS REQUIRED: Next, let workers know what they can do to protect themselves from cold stress risks. Start by explaining that warm and dry clothing is crucial to preventing cold stress and list the items workers should wear when performing work in cold conditions, which may include:

  • At least 3 layers of loose fitting clothing, including:
    • An inner layer of wool, silk or synthetic materials to insulate the body against moisture;
    • A middle layer of wool or synthetics for insulation in case the outer layer gets wet; and
    • An outer layer to protect against wind and moisture and that’s ventilated to prevent overheating;
  • A hat or hood to keep heat from escaping from the worker’s head;
  • A knit mask to cover the worker’s face and mouth;
  • Gloves that are insulated and, if necessary, water-proof; and
  • Insulated and water-proof boots or other footwear.

EXPLAIN THE ROLE OF FIRST AID: Tell workers that when doing work involving cold stress hazards, they need to be aware of the dangers and look out for each other. Explain that to do this effectively, each worker needs to:

  • Be able to recognize the signs and symptoms of each form of cold stress; and
  • Understand what to do in response to such signs and symptoms.

LIST SIGNS & TREATMENTS: Last but not least, describe the signs, symptoms and appropriate first aid treatment of each form of cold stress:

Condition Signs & Symptoms First Aid Treatment
Frostbite * Bluish or pale, waxy skin
* Numbness
* Tingling
* Stinging
* Blisters
* Get into warm room ASAP
* Do NOT rub affected area
* Do NOT use heating pad or heat lamp to warm (which may cause burns)
* Do NOT break blisters
* Loosely cover and protect affected area from contact
* Give victim warm, sweetened drinks
Trench foot * Reddening of skin
* Numbness
* Leg cramps
* Tingling pain
* Swelling
* Blisters
* Bleeding under skin
* Foot turns dark purple, blue or gray
* Remove shoes, boots, wet socks
* Dry feet
* Do NOT let victim walk as this may cause tissue damage to the feet
Chilblains * Redness
* Itching
* Blistering
* Inflammation
* Ulceration
* Do NOT scratch the itch
* Slowly warm skin
* Use corticosteroid creams to relieve itching and swelling
* Keep blisters/ulcers clean and covered
Hypothermia Early Symptoms
* Shivering
* Fatigue
* Loss of coordination
* Confusion/Disorientation

Late Symptoms
* No shivering
* Blue skin
* Dilated pupils
* Slowed pulse & breathing
* Loss of consciousness

* Request immediate medical help
* Move victim to warm area or room
* Remove wet clothing
* Warm center of body—chest, neck, head, groin
* Have victim drink warm beverages without alcohol
* When body temperature increases, keep victim dry and wrapped in a warm blanket—including the head and neck
* Begin CPR if victim has no pulse