The Dangers And Effects Of Cold Stress
Cold stress or hypothermia can affect workers who are not protected against cold. The cold may occur naturally (e.g., from weather conditions) or be created artificially (e.g., from refrigerated environments). Cold is a physical hazard in many workplaces. When the body is unable to warm itself, serious cold-related illnesses may occur, leading to permanent tissue damage and even death.
Workplaces exposed to cold, wet, and/or windy conditions include
- Roofs
- Open or unheated cabs
- Bridges or other projects near large bodies of
- water
- Large steel structures that retain cold or are
- exposed to cold
- High buildings open to the wind
- Refrigerated rooms, vessels, and containers.
This section provides information on
- Effects of cold stress
- Factors that can worsen these effects
Knowing this information can help construction workers avoid hypothermia and frostbite.
Health Hazards
Exposure to cold causes two major health problems:
- Hypothermia
- Frostbite
Hypothermia
When the body can no longer maintain core temperature by constricting blood vessels, it shivers to increase heat production. Maximum severe shivering develops when the body temperature has fallen to 35°C (95°F).
Signs and Symptoms
The most critical aspect of hypothermia is the body’s failure to maintain its deep core temperature. Lower body temperatures present the following signs and symptoms:
- Persistent shivering—usually starts when the core temperature reaches 35°c (95°f)
- Irrational or confused behavior
- Reduced mental alertness
- Poor coordination, with obvious effects on safety
- Reduction in rational decision-making.
In addition, acute exertion in cold can constrict blood vessels in the heart. This is particularly important for older workers or workers with coronary disease who may have an increased risk of a heart attack.
First Aid
Stop further cooling of the body and provide heat to begin rewarming.
- Carefully remove casualty to shelter. Sudden movement or rough handling can upset heart rhythm.
- Keep casualty awake.
- Remove wet clothing and wrap casualty in warm covers.
- Rewarm neck, chest, abdomen, and groin—but not extremities.
- Apply direct body heat or use safe heating devices.
- Give warm, sweet drinks, but only if the casualty is conscious.
- Monitor breathing. Administer artificial respiration if necessary.
- Call for medical help or transport casualty carefully to the nearest medical facility.
Frostbite
Frostbite is a common injury caused by exposure to a severe cold or by contact with extremely cold objects. It occurs more readily from touching cold metal objects than from exposure to cold air. That’s because heat is rapidly transferred from skin to metal.
The body parts most commonly affected by frostbite are the face, ears, fingers, and toes. When tissue freezes, blood vessels are damaged. This reduces blood flow and may cause gangrene.
Signs and symptoms
Frostbite symptoms vary. They are not always painful but often include a sharp, prickling sensation. The first indication of frostbite is skin that looks waxy and feels numb. Once tissues become hard, the case is a severe medical emergency.
Severe frostbite results in blistering that usually takes about ten days to subside. Once damaged, tissues will always be more susceptible to frostbite in the future.
First Aid
- The warm frostbitten area gradually with body heat. Do not rub.
- Don’t thaw hands or feet unless medical aid is distant and there is no chance of refreezing. Parts are better thawed at a hospital.
- Apply sterile dressings to blisters to prevent breaking. Get medical attention.