Cold Stress Toolbox Talk

Cold Stress Toolbox Talk

Cold Stress Toolbox Talk: Now that the months of lower temperatures have arrived, workers are exposed to cold stress that can cause serious health problems. We will cover today not only the cold stress but also the risks you face exposure to cold stress at work and cold stress prevention. We are in the traditionally coldest week of the year, a more than favourable time to cold stress toolbox talk due to the cold.

It’s no secret that working outside in low temperatures can be dangerous. The risk of slipping and falling can increase as the weather gets colder. But there is also a risk in wiring that is handled during inclement weather. Are you ready for Cold Stress Toolbox Talk (OSHA COLD STRESS)

What is cold stress?

A negative thermal load (excessive heat loss) to which workers are exposed as a result of the combined effect of physical and climatic factors (environmental conditions, physical activity and work clothes) that affect heat exchange. In response to this load, the body resorts to a “series of adjustment mechanisms necessary to increase internal heat generation and reduce its loss”, seeking “maintenance of internal temperature”.

Cold stress would be, in short, that discomfort that occurs when the human body is forced to make an extra effort to maintain its internal temperature, which must be around 37ºC in a cold situation.

For its part, the human body, to combat cooling, resorts to mechanisms such as cutaneous vasoconstriction (which allows the internal heat to be conserved) or shivering, a reflex and involuntary act that increases the body’s heat production which has been lost due to convection (by the effect of the wind), by conduction (by contact with a cold surface) or by the respiratory tract.

Cold Stress Toolbox Talk
Cold Stress Toolbox Talk

Effects of exposure to cold at work

From temperatures below 15ºC, the sensation of thermal discomfort may begin, and below 5ºC the risk should be considered immediate. We have as a reference that exposure to cold can start to be considered dangerous when the body temperature drops to 35º, which manifests itself in the form of an intense tremor and can generate alterations in the vascular system. But what are the effects of exposure to cold at work?

When there is an excessive loss of heat in all or part of the body, a sensation of cold, discomfort or even pain can occur. The drop in temperatures in the work area can cause a decrease in manual dexterity and mental, and physical capacity. It can have respiratory effects (from irritations to bronchospasms), cardiovascular effects and cold injuries (by cooling without freezing and by general cooling of the body with hypothermia, the most serious of all).

Health consequences of cold stress

  • Respiratory Effects: This may cause respiratory tract irritation, inflammatory reactions, and bronchospasm.
  • Cardiovascular effects: increasing blood pressure as a consequence of peripheral vasoconstriction.
  • Cold injuries: frostbite, hypothermia, trench foot, chilblain when the internal temperature drops below 35ºC.

Temperatures above freezing can be dangerous if a person is chilled by wind, rain, heat, or immersion in cold water. People with health conditions such as hypertension, hypothyroidism, and diabetes may be more susceptible to climate change. A lack of shivering can indicate a serious problem, especially if the person has been shivering previously. This may indicate that hypothermia is being acquired.

Even a slight loss of coordination or clumsiness in handling tools and equipment may be another indication that hypothermia is developing. Rubbing, using hot water, or using other methods to try to rewarm a frostbite area can be more damaging. If an area is suspected to have frozen it is best left to medical professionals to rewarm the area. Following are the disease, Cold stress symptoms and first aid measures:

Trench foot

Trench foot (also known as immersion foot) is another cold stress injury that can occur when the skin is exposed to long periods of moisture. Wet skin loses heat 25 times faster than dry skin, which means that this immersion can occur in temperatures as low as 15°C.

World War I trench foot, also known as immersion foot, is the name given to the disease first described during World War I to soldiers who had spent the winter in trenches flooded with water. What does it consist of…The name of this disease was established in the First World War. Soldiers would lie tirelessly in waterlogged trenches for weeks at freezing temperatures.

The symptoms appeared when the feet were exposed for prolonged periods to the effects of humidity and cold. This combination of cold and moisture softened the skin, causing wounds and tissue infection. If the disease was not treated in time, it gave rise to gangrene, requiring the amputation of the limb.

Usually, the first symptoms are itching, cold skin, pain, numbness and tingling. Subsequently, the foot usually swells and the skin becomes reddish or bluish, with suppuration or bleeding, resulting from a poor vascular supply. Soldiers wearing tight or waterproof boots,

Trench foot was caused by poor nutrition, dehydration, inappropriate footwear and wet socks. People with excessive sweating were more likely to contract this disease. The way to combat it was to have clean, dry socks on hand at all times.

Phases of the disease – First phase of spasm due to cold and humidity, in which the blood vessels contract, making it difficult for oxygen to reach the foot, which appears numb, corked, cold and cyanotic.

Cold Stress Toolbox Talk
Cold Stress Toolbox Talk

The second phase of revascularization is when removing the foot from where it was, and moving to a drier and warmer environment. Intense vasodilation occurs, and the foot becomes reddish, edematous and shiny. Blood-filled blisters and intense throbbing pain develop, feet claw back, and recovery begins.

This stage is the most delicate because if adequate revascularization of the tissues is not given, necrosis and gangrene appear. If the trench foot is not treated early or the treatment is not effective, the third phase is entered in which the foot can enter ischemia again.


Chilblains are ulcers formed by damage to the blood vessels in the skin, due to repeated exposure to temperatures just above freezing and as high as 60°F. Chilblains usually clear up within one to three weeks, especially if the weather gets warmer. You may have recurrences seasonally for years.

Chilblains don’t usually result in permanent injury.  if left untreated it can be an infection, which may cause severe damage. The best approach to chilblains is to avoid developing them by limiting your exposure to cold, dressing warmly and covering exposed skin.

cold stress toolbox talk
cold stress toolbox talk

Cold stress and Hypothermia

Hypothermia is a disorder in which the body depletes stored energy and stops producing heat, according to the CDC, it usually occurs after prolonged exposure to cold temperatures. The primary treatments for hypothermia are methods to warm the body to a normal temperature.

Someone with hypothermia is usually unaware of their condition because the symptoms often start gradually. Additionally, the fuzzy thinking associated with hypothermia impedes self-awareness. Confused thinking can also lead to risky behaviour.


Frostbite is an injury to the body from exposure to extremely low temperatures, often affecting the nose, ears, cheeks, chin, fingers and toes. Frostbite is an injury caused by the freezing of the skin and underlying tissues.

Cold Stress Toolbox Talk
Cold Stress Toolbox Talk

Symptoms include cold skin and a prickling feeling, followed by numbness and inflamed or discoloured skin. Exposed skin in cold, windy weather is most vulnerable to frostbite, but it can affect skin covered by gloves or other clothing.



First aid

Numbness.Check for hypothermia. Get emergency medical help if you suspect hypothermia. Signs of hypothermia include intense shivering, drowsiness, confusion, fumbling hands and slurred speech.
Dolores.Protect your skin from further damage. If there’s any chance the affected areas will freeze again, don’t thaw them. If they’re already thawed, wrap them up so that they don’t refreeze.
Tingling or burning.         

If you’re outside, warm frostbitten hands by tucking them into your armpits.  And don’t walk on frostbitten feet or toes if possible.

At first, cold skin and a prickling feeling
Skin that looks red, white, bluish-white, greyish-yellow, purplish, brown or ashen, depending on the severity of the condition and usual skin colour
Hard or waxy-looking skin


Get out of the cold. Once you’re in a warm space, remove wet clothes and wrap them up in a warm blanket.

Clumsiness due to joint and muscle stiffness


If a thermometer isn’t available, test the water by placing an uninjured hand or elbow in it — it should feel very warm, not hot. Soak for 20 to 30 minutes or until the skin becomes its normal colour or loses its numbness.  This can cause burns.



Blistering after rewarming, in severe cases


Drink warm liquids. Tea, coffee, hot chocolate or soup can help warm you from the inside. Don’t drink alcohol.
Monitor breathing. A person with severe hypothermia may appear unconscious, with no apparent signs of a pulse or breathing. If the person’s breathing has stopped or appears dangerously low, begin CPR immediately if you’re trained.
Consider pain medicine.
Know what to expect as skin thaws. You’ll feel tingling and burning as the skin warms and normal blood flow returns

Cold stress prevention

Many factors influence each person’s reaction to cold, such as age, general health or morphology. However, there are certain preventive measures, both general and specific, that can be used by all workers.

  1. Technical and work organization measures

Even if the work is carried out outdoors, it is advisable to have a cold stress shelter (with a heater), where you can consume warm water. In addition, in interior works, installing insulation or automatic mechanisms that reduce the manual workload are two very appropriate measures. On the other hand, it is also convenient to plan outdoor activities considering the weather forecast whenever possible.

  1. Personal preventive measures

To reduce the loss of body heat, it is convenient to select the appropriate clothing that also facilitates the preserve heat. Other preventive measures are a decrease in coffee consumption, the replacement of damp clothing, as well as the control of the work rhythm. In addition, the supply of external heat is also essential, establishing breaks to warm up in a designated area.

Finally, it is very important before facing cold situations at work that the employees themselves are trained because it is an essential tool to control both the risks and the measures to be adopted.

Related post:

Thermal Comfort Definition

Heat stress hazards and control measures

If it is impossible to eliminate risks due to cold, it is necessary to evaluate them to find out if they can be considered acceptable for health or if, on the contrary, it is necessary to apply measures to reduce them to acceptable levels. A perfect prevention measure would be the installation of thermometers in certain areas so that if it is observed that certain temperatures are reached, workers have the right to stop the activity for some time to recover and drink warm water.

Material Handling and Storage

In outdoor environments, we must take into account a series of tips that can help us maintain body temperature and avoid bigger problems. Good practices that can help us can be:

  • Wear suitable protective clothing against the cold.
  • If the temperatures are very low, always wear eye protection and hand protection.
  • Protect workers’ extremities to avoid localized cooling.
  • Provide workers with warm clothing and appropriate footwear.
  • Wear windproof clothing to reduce the effect of airspeed.
  • Perform medical examinations to detect early vascular and skin disorders.
  • Periodically measure the temperature and air speed to control the two thermo- hygrometric variables with the greatest influence on the risk of cold stress.
  • Decrease the time spent in cold environments to minimize heat loss.
  • Control the pace of work and schedule breaks to recover lost heat.


The main cause of thermal stress is the existence of unfavourable work environments, that is, the environment is not comfortable for workers, either for their stay in a certain place or for carrying out their tasks. In these cases, the human body cannot maintain its necessary internal temperature (around 37ºC) since it is unable to balance the losses and gains of heat resulting from the environmental temperature.

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2 responses to “Cold Stress Toolbox Talk”

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    Kulamani Gouda


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