Working In Cold Environments

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Working In Cold Environments
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Things to Consider

• Where is cold a problem?
• Effects of cold on the body
• Regulations covering cold
• Risk Assessment
• Controls

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Where is cold a problem?

• Outside work
• Food production
• Chilled
• Frozen
• Controlled environments
• Warehousing
• Winter driving

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Why Be Concerned?

• The body needs to maintain a core temperature of
  37C. This thermal balance must be maintained.

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How is heat lost from the body?

• Radiation
• Difference in Temp between body and surrounding
  environment. Greater the more skin is exposed
• Conduction
• Heat loss through direct contact with cooler
  object.

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How is heat lost from the body?

• Convection
• Loss of heat to the surrounding air as the air
  moves across the surface of the skin. Heat loss
  depends upon air temperature and wind speed. Wind
  speed ceases to have an increased effect above
  50mph

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How is heat lost from the body?

• Evaporation
• Heat loss due to the conversion of water from a
  liquid to a gas
• Sweating to remove excess heat
• Insensible perspiration to maintain humidity of
  70 next to skin. Particularly in cold dry
  environment
• Respiration as heated air enters the lungs and
  is exhaled with an extremely high moisture
  content

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Thermal Balance

• To survive in cold the body must balance the heat
  losses with the heat production of the body
• To look at this we must consider the Cold
  Challenges on the body. These are
• Temperature
• Wind
• Wetness

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Thermal Balance

• Heat Production
• - Food Intake
• - Activity
• - Shivering

Hypothermia
Heat Production - Food Intake - Activity -
Shivering
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Personal Factors

• Size and shape of the body (surface to volume
  ratio)
• Layer of fat under the skin
• Decreased the blood flow through the skin and
  outer parts of body
• Insulation (layering and type of clothing)

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Personal Factors

• Response in Men and Women
• Core cools more slowly in women. However, they
  are not able to create as much metabolic heat
• Extremities cool more quickly in women
• As a result women are at a greater risk of cold
  injury

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Personal Factors

• Predisposing conditions
• Age old and very young
• Diseases of the blood circulatory system
• Injuries resulting in blood loss or altered blood
  flow
• Previous cold injury
• Fatigue
• Consumption of alcohol or nicotine

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Personal Factors

• Acclimatisation
• People do not acclimatise to cold very well
• Frequently exposed body parts can develop some
  degree of tolerance to the cold

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Effects of cold on the body

• Impairment of complex mental processes
• Manual tasks impaired due to loss of dexterity
• Blood redirected from extremities to keep core
  warm
• Reduced muscular strength

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Effects of cold on the body

• Stiffened joints
• Reduced mental alertness
• Corneas of eyes can freeze with high wind chill
• Cold injuries

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Cold injuries

• Non freezing
• Freezing
• Hypothermia

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Non Freezing Injuries

• Chilblains
• Mild injury caused by prolonged and repeated
  exposure for several hours to air tempretures
  from 0c to 16c. Redness of skin, swelling,
  tingling and pain
• Immersion foot
• Where foot has been wet but not freezing cold for
  days or weeks. Can occur up to 10c. Primary
  injury to nerve and tissue. Symptoms include
  tingling, numbness, itching, pain, swelling of
  legs, feet or hands, Blisters may develop.
  Gangrene can develop

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Non Freezing Injuries

• Trenchfoot
• Wet cold disease. Similar to Immersion Foot but
  occurs at lower temperatures. Onset can range
  from hours to many days. Average three days.

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Freezing Injuries

• Frostnip
• Mildest form of freezing injury. Occurs when ear
  lobes, noses, cheeks, fingers or toes are exposed
  to cold and top layers of skin freeze. Affected
  area turns white and feels numb
• Frostbite
• Common injury on exposure to extreme cold or
  contact with extremely cold objects. May occur on
  contact with cold gases. Occurs when tissue temp
  falls below 0c or blood flow is obstructed. Blood
  vessels can be severely and permanently damaged.
  In mild cases symptoms include inflammation of
  skin accompanied by slight pain. Severe cases can
  lead to burning or prickling sensations resulting
  in blisters. Frostbitten skin is susceptible to
  infection leading to gangrene. Can lead to
  amputations

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Hypothermia

• This is the condition that is caused by the
  bodies core temperature dropping.
• First symptom is feeling of cold and pain in
  exposed parts of body
• As temp drops the feeling of cold and pain
  diminishes

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Hypothermia

• Muscular weakness and drowsiness are experienced.
  This is the onset of the hypothermia and occurs
  when the core temp reaches 33c
• Additional symptoms include interruption of
  shivering, diminished consciousness and dilated
  pupils
• 27c coma, 20c heart stops, 17c brain stops

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Regulations

• HSaW Act 1974 General Duties Safe working
  Environement
• Management Regs Reg 3 Risk Assessment
• Workplace Regs Reg 7 Tempreture in all
  workplaces inside buildings shall be reasonable
  during working hours

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Regulations

• Acop goes on to suggest minimum levels of
• 16c sedentary work
• 13c physical effort
• Acop allows for special circumstances such as
  food where lower temps are required and it is
  impractical to take other steps localised
  chilling etc.

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Risk Assessment

• Use the normal hierarchy
• Is cold process required?
• Can exposure to cold be prevented?
• Consider how people may be affected by the cold?
• Select suitable controls for residual risk
• First Aid Risk Assessment

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Controls

• Warm working station within cold area
• Exposure product to warm room for short period
• Pre-chill products
• Chilling stations on line
• Floor matting to raise feet off cold floors

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Controls

• Suitably heated rest rooms
• Work rest regimes to limit time spent in cold
  area
• PPE free to user and suitable for conditions
• Training for First Aiders

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Further information

• BS79151998 Ergonomics of the thermal Environment
  Guide to the design and evaluation of working
  practices for cold indoor environments
• HSE Information Sheet FIS3(rev1) March 1999