Chapter 7
COLD ENVIRONMENTS*

David W. DeGroot and Laura A. Pacha**

OCCUPATIONAL SETTING

Cold is a physical hazard that may affect workers, both indoors and outdoors, virtually anywhere in the world. Workers at greater risk include construction workers, farmers, fishermen, utility workers, lumberjacks, soldiers, petroleum workers, police, firefighters, postal workers, butchers, and cold storage workers. For the purpose of this chapter, an extreme cold environment exists when ambient temperature is <0°C/32°F.1

Cold injuries may be either freezing (frostbite) or nonfreezing (trench/immersion foot and hypothermia) and localized or systemic. While they occur sporadically in civilian populations, in both occupational and recreational settings, cold injuries have been a significant problem in military campaigns throughout history. The armies of Xenophon (400 BC), Hannibal (218 BC), and Napoleon (1812–1813) experienced significant numbers of cold injuries.2 Despite numerous advances in our understanding of thermoregulation during cold stress, and in the development of protective clothing, cold injuries continued to affect military operations in the twentieth century, notably in the trench warfare of World War I (hence the immersion foot synonym trench foot), the German experience in Russia during World War II, and the British experience in the Falkland Islands in the 1980s.3 The incidence or frequency of cold injury in the civilian sector is much more difficult to determine; unlike the military, hypothermia, frostbite, and other cold injuries are not reported to health authorities for surveillance purposes. Cold weather is not a barrier to safe and successful work performance, and it is important to remember that “a man in the cold is not necessarily a cold man.”4

MEASUREMENT ISSUES

Two important concepts for evaluating cold exposures are the body core temperature and the wind chill index. Body core temperature is measured by a low-reading rectal thermometer. In the hospital, an esophageal temperature probe is the preferred instrument to monitor core temperature. Measurement at other anatomical sites, including sublingual, temporal, and axillary, will result in an inaccurate reading of body core temperature and is not recommended.5 Ambient temperature should be measured by thermometers capable of measuring temperatures down to at least −40°C (−40°F). The wind chill index is used to determine the risk of cold injury by estimating the relative cooling ability of a combination of air temperature and wind velocity. The wind chill index is measured as the equivalent chill temperature (Table 7.1). In outdoor work situations, wind speed should be measured and recorded, together with air temperature, whenever the air temperature is below −1°C (30.2°F). The equivalent chill temperature should be recorded with these data whenever the equivalent chill temperature is below −7°C (19.4°F).6

TABLE 7.1 Cooling power of the wind on exposed flesh expressed as equivalent temperature (under calm conditions).

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Threshold limit values (TLVs®) for cold stress are based on the wind chill index, and they require workplace temperature monitoring.6 Suitable thermometry should be available at any workplace where the environmental temperature is below 16°C (60.8°F), and whenever the air temperature at a workplace falls below −1°C (30.2°F), the dry bulb temperature should be measured and recorded at least every 4 hours.

EXPOSURE GUIDELINES

Cold stress TLVs® are intended to protect workers from the severest effects of cold stress (hypothermia) and cold injury (frostbite) and to define exposures to cold working conditions under which it is believed that nearly all workers can be repeatedly exposed without adverse health effects.6 The objectives of TLVs® are to prevent the body core temperature from falling below 36°C (96.8°F) and to prevent cold injury of body extremities. For a single, occasional exposure to a cold environment, a drop in core temperature to no lower than 35°C (95°F) should be permissible. However, some clinical signs and symptoms of cold injury would be expected at that temperature. Continuous, vigorous shivering should be taken as a danger sign and cold exposure should be terminated immediately. Practically speaking, useful physical or mental work is limited once severe shivering occurs.

Whole-body protection, in the form of adequate, insulated, and dry clothing, should be provided if work is performed in air temperatures below 4°C (39.2°F). Nomograms for the determination of required clothing insulation are available.7 For unprotected skin, continuous exposure should not be permitted when the equivalent chill temperature is below −32°C (−26.5°F).

Provisions for additional total body protection, such as shielding the work area and wearing wind-resistant and water-repellent outer clothing, are required if work is performed at or below 4°C (39.2°F). If work is performed continuously in the cold at an equivalent chill temperature below −7°C (19.4°F), heated warming shelters (e.g., tents, cabins) should be available nearby and used at regular intervals (Table 7.2). Heavy shivering, frostnip, a distant gaze, a feeling of excessive fatigue, drowsiness, irritability, or euphoria are indications for immediate return to the shelter.

TABLE 7.2 Threshold limit values® for work/warm-up schedule for 4-h shift.

Source: From ACGIH®, 2015 TLVs® and BEIs® Book. Copyright 2015. Reprinted with permission.

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NORMAL PHYSIOLOGY

Body temperature is the sum of heat produced internally, plus heat gain and loss from the environment, as described by the heat balance equation presented in Chapter 6. Briefly, body core temperature is maintained when the sum of the terms of the equation equals zero. Heat is produced via metabolism and shivering, while heat is lost through radiation, conduction, convection, and evaporation. While heat can be gained via radiation, conduction, or convection, this is unlikely in a cold environment. The most significant heat loss in the cold occurs with cold water immersion or with exposure to low air temperature and strong winds while in wet clothing.

The preoptic area of the anterior hypothalamus controls body core temperature in response to both heat and cold. The hypothalamus is responsible for initiating the two main defenses against cold: peripheral vasoconstriction and shivering. Body core temperature is maintained by decreasing heat loss (peripheral vasoconstriction) and increasing heat production (shivering). Increasing physical activity also increases heat production. Peripheral vasoconstriction is the initial response to reduced skin temperature. Vasoconstriction directs blood away from the surface of the body to the core, thereby increasing tissue insulation and conserving heat. Shivering is produced by involuntary muscle contraction and results in increased metabolic heat production, which replaces heat being lost. There is an associated increase in the respiratory rate and heart rate. Shivering may increase the metabolic rate two- to fivefold.7 However, if body core temperature is reduced with continued cooling, the metabolic, respiratory, and heart rates decrease.

With continued cold exposure, cold-induced vasodilation (CIVD) alternates with peripheral vasoconstriction to conserve body heat and, at the same time, intermittently conserve dexterity and function of the extremities via periodic rewarming.8 Blood shunting from the skin to the body core due to vasoconstriction results in cold diuresis and decreased fluid volume. Specialized thermoreceptors in the skin detect the sensation of cold and provide the individual with the sensation of thermal comfort. However, when the skin freezes as during the development of frostbite, the sensation of cold is lost and the individual may be unaware, which underscores the importance of buddy checks.

There is some evidence that humans are capable of minor physiologic acclimatization to the cold, which manifest in three patterns: habituation, metabolic acclimatization, and insulative acclimatization, depending on the nature of the exposure.9 The physiological adjustments to chronic cold exposure are slower to develop, less pronounced, and less practical in relieving thermal strain and preventing cold injury, when compared to the effects of heat acclimatization. Workers in a cold environment require 10–15% more calories, as additional heat is expended working in heavy, protective clothing, and caloric expenditure increases in order to maintain normal body core temperature.10

The importance of behavioral thermoregulation, or how an individual reacts in response to cold stress, on the prevention of cold weather injuries cannot be overstated. A cursory glance at the widely divergent environments in which humans can live and work illustrates the importance of behavioral thermoregulation. When an individual is from a climate where cold stress is minimal or absent, or is enduring his or her first season in extreme cold, the risk of suffering a cold injury is increased.11,12 Such individuals lack the experience of prior cold exposure to guide their decision-making regarding the proper selection, wear, and use of protective clothing and equipment. Most cold weather injuries are preventable, provided that the appropriate clothing and equipment is available and utilized.

PATHOPHYSIOLOGY OF INJURY

The three major cold weather injuries are freezing injury (frostbite), hypothermia, and nonfreezing injury (formerly trench/immersion foot or pernio). Additionally, there are cold-associated problems, which include accidental injury, sunburn, snow blindness, carbon monoxide poisoning, dehydration, and cold urticaria. In the following sections, we will address the pathophysiology, diagnosis, and treatment of the major cold weather injuries.

Frostbite

Mild frostbite, sometimes called frostnip, is a reversible, superficial freezing cold injury that leads to no loss of tissue. Frostbite is the localized freezing of tissue, with formation of ice crystals and disruption of the cells. The capillary walls, particularly the endothelial cells, of the frostbitten area are damaged, increasing cell wall permeability. Fluid is released into the tissues and is accompanied by local inflammation. The most peripheral parts of the body, such as the toes, fingers, nose, ears, and cheeks, are the most common sites of freezing cold injury. The incidence of freezing cold injuries in the United States is unknown.

Hypothermia

Hypothermia is the lowering of core body temperature below 35°C (95°F). Hypothermia results when sustained heat loss to the environment exceeds heat production. Below-freezing temperatures are not necessary for the development of hypothermia, as the effects of wind chill, water immersion, rain, and/or sweating dampening the innermost layer of clothing can contribute. Air temperature as “warm” as 18.3°C (65°F) or at water temperatures up to 22.2°C (72°F) may be sufficient to cause hypothermia, especially if the duration of exposure is prolonged.

While the incidence of hypothermia is unknown, approximately 700 deaths in the United States each year are attributed to hypothermia, with most occurring in persons aged 60 years or older.13 Death due to cold exposure occurs more frequently in men than in women. Hypothermia is associated with prolonged environmental exposure to the cold, physical exertion, wind, and skin wettedness. The insulating capability of wet clothing is reduced because the layers of trapped, dead-space air are lost. Since the thermal conductivity of water is 25 times that of air, hypothermia occurs rapidly in cold water (Table 7.3).14

TABLE 7.3 Survival times in cold water.

Source: Adapted from United States Search and Rescue Task Force, Cold Water Survival Guide (http://www.ussartf.org/cold_water_survival.htm). The time estimate variability is due to difficulty in predicting survival time, which is influenced by numerous variables.

Water Temperature, °C (°F) Exhaustion or Unconsciousness Survival Time
>21–27 (70–80) 3–12 hrs 3 hrs – indefinite
16–21 (60–70) 2–7 hrs 2 hrs – indefinite
10–16 (50–60) 1–2 hrs 1–6 hrs
4–10 (40–50) 30–60 min 1–3 hrs
0–4.0 (32–40) 15–30 min 30–90 min
<0 (32) <15 min 15–45 min

Nonfreezing cold injury

Previously referred to as trench or immersion foot, nonfreezing cold injury (NFCI) is due to prolonged exposure to cold water. It usually occurs in dependent parts of the lower extremities in relatively immobile workers who are partially immersed in cold water. Minor trench/immersion foot injuries occur after 3–12 hours of exposure; significant tissue damage occurs after 12 hours to 3 days of exposure; and severe amputation-type injuries occur beyond 3 days of exposure. Prevention of NFCI is most important, because treatment of this injury is relatively ineffective. As NFCI is relatively infrequent in non-military scenarios, the interested reader is directed elsewhere for more in-depth discussion.15

Intense and prolonged cold-induced peripheral vasoconstriction is understood to initiate NFCI, in which the neuro-endothelio-muscular components of the walls of blood vessels are affected. Depending on the severity of the injury, clinically, there are four stages to the injury and recovery process. The first stage occurs during cold exposure; the key diagnostic criterion is complete local anesthesia and loss of proprioception. The intense ischemic vasoconstriction is responsible for the visual appearance of affected tissue, which initially appears bright red but often changes to a paler color before becoming almost completely white. The second stage follows cold exposure and typically only lasts for several hours. During this stage tissue is reperfused, and skin color changes to a mottled pale blue, while anesthesia to pain, touch, and/or temperature remain. The third stage is characterized by hyperemia, persistence of pain in the affected area, and anhydrosis. Pain relief using conventional analgesics and anti-inflammatory agents is usually completely unsuccessful. This stage may last for a few days or several months in more severe cases. The fourth and final stage, once hyperemia has resolved, may last for weeks, months, or even for the remainder of their lifetime in some individuals. This stage is often characterized by long-lasting cold sensitivity, hyperhydrosis, and related increased risk of recurrent fungal infection.

Cold-associated problems

In addition to injuries directly attributable to cold exposure, there are several problems associated with cold, such as cold urticaria, carbon monoxide poisoning, sunburn and snow blindness, accidental injury, and dehydration. Cold urticaria, in susceptible individuals, is characterized by local or systemic formation of wheals, with redness, swelling, and edema of the skin associated with cold exposure. The severity of cold urticaria is proportional to the rate of skin cooling and not to the absolute temperature,16 and treatment is limited to antihistamines for relief of swelling.

Carbon monoxide (CO) poisoning is another common event in cold environments because of the use of unvented combustion heaters. CO poisoning should be considered in all cold, unresponsive patients. Symptoms include an initial headache, followed by confusion, dizziness, and somnolence.

Snow, ice, and reduced visibility increase the incidence of accidents in the cold, especially slips, trips, and falls. Snow blindness and sunburn may occur when the skin and eyes are unprotected from the ultraviolet rays of the sun and their reflection off the snow.

Body fluid requirements are no different in cold than in temperate environments. Because individual perception of thirst and the need to drink is suppressed in the cold, dehydration occurs when fluid intake is reduced. Individuals may also voluntarily dehydrate in an effort to avoid urination, which may present a nuisance when warm restroom facilities are not available. Dehydration results in decreased mental alertness, impaired cognitive ability, and reduced work capacity, and, therefore, the importance of fluid replacement should not be overlooked during cold exposure.

DIAGNOSIS

Hypothermia is insidious in onset and may be difficult to identify. In the setting of exposure to cold, hypothermia should be suspected. An appropriate clinical history, physical examination, and rectal temperature must be performed to make the diagnosis. The signs and symptoms of hypothermia may begin to appear at a body temperature of 36.1°C (97°F). Maximum shivering occurs at 35°C (95°F). Progressive decrease in core temperature results in confusion, unusual behavior, impaired coordination, slurred speech, drowsiness, weakness, lethargy, disorientation, and unconsciousness. There is slowing of the heart rate and respiratory rate. The pulse is weak, and blood pressure is decreased. Movements are slow, and deep tendon reflexes are reduced.

With body core temperatures from 32.2°C (90°F) to 35°C (95°F), peripheral vasoconstriction and shivering occur. Between 25°C (77°F) and 32.2°C (90°F), shivering is diminished, and peripheral vasoconstriction is lost. Below 25°C (77°F), there is a failure of all heat regulatory and heat conservation mechanisms.16 Loss of consciousness occurs between 30°C (86°F) and 32°C (89.6°F). Loss of central nervous system function and coma occur below 28°C (82.4°F). Apnea occurs below 27°C (80.6°F) and asystole below 22°C (71.6°F).

TREATMENT

The degree of the cold and the duration of exposure are the two most important factors in determining the extent of a frostbite injury.17 The keys to frostbite treatment are to protect the tissue from further injury and to increase blood flow to the interface between injured and uninjured tissue.

Frostbite may be classified as superficial or deep. Skin freezes at about −2°C (28°F). Superficial frostbite involves the skin and subcutaneous tissue, and there is no loss of tissue. The skin is gray–white, dry, and hard, with loss of sensation. With rewarming, there is pain, redness, and swelling of the skin, and blisters containing clear fluid may form. Deep frostbite involves the skin and subcutaneous tissue, as well as deeper tissues, including muscle, and bone. With deep frostbite, the affected area is pale, cold, and solid, and there is eventual loss of tissue. Formation of deep hemorrhagic blisters, death of tissue (necrosis), and ulceration occurs. Dry gangrene may develop, with autoamputation of the dead tissue. Superficial frostbite corresponds to first and second degree frostbite, under older classification systems, while third and fourth degree frostbite together are classified as deep frostbite. Frostnip and mild frostbite may be rewarmed in the workplace by placing the injured part in the armpits or the groin. In more severe injuries, if there is absolutely no possibility of the tissue refreezing, the frozen tissue may be rewarmed outside the hospital. The rewarmed part should be insulated and the patient transported to the hospital. Care must be taken not to apply excessive heat to rewarm frozen tissue, since this may produce a devastating secondary burn injury. Ideally, thawing of frozen tissue should occur in the hospital. Tissue should be rapidly rewarmed in a controlled-temperature water bath (40–42.2°C (104–108°F)). Attention should also be given to warming the whole body.

Hypothermia is a medical emergency. Only conscious patients with mild hypothermia (above 32.2°C (90°F)) should be rewarmed in the workplace.18 For conscious patients their core temperature should be determined, and the patients should be prevented from losing additional body heat by insulating them and then rewarming them with passive external rewarming. They may be placed in a sleeping bag, wrapped in blankets, or exposed to a radiant heat source. Shivering and voluntary physical activity, such as walking, should be encouraged to generate body heat. Warm, decaffeinated, and nonalcoholic drinks should be provided to rewarm the body and replace lost fluids.

Severely hypothermic (below 28°C (82.4°F)) patients and unconscious victims of hypothermia are in a life-threatening situation. They should be handled gently, insulated, provided with intravenous fluids (5% dextrose), and transported to definitive medical care for physiologic monitoring, controlled rewarming, and management of sequelae. Peripheral pulses should be checked before initiating CPR, in order to avoid disturbing a faint but otherwise normal cardiac rhythm.19 Attempts to rewarm these hypothermia victims in the workplace should be avoided.19

In severely hypothermic individuals, a body core temperature of less than 25–26.1°C (77–79°F) is a poor prognostic sign. At these temperatures, the myocardium is easily irritated and ventricular fibrillation or asystole are significant risks. Resuscitative measures such as active external rewarming, active core rewarming, cardiopulmonary resuscitation, or defibrillation should not be performed unless cardiac monitoring capability is available.19 Aggressive rewarming with extracorporeal blood warming has been associated with good long-term prognosis in a group of patients suffering severe hypothermia with cardiac arrest.20 Patients should be transported to a definitive care facility as quickly as possible. If cardiopulmonary resuscitation is started, it must be continued until the patient has been warmed to 36°C (96.8°F). Since metabolic processes are slowed with hypothermia, asystolic survival times are prolonged. Drowning may occur with sudden immersion in cold water, and resuscitation efforts should continue for the same reasons. Expected survival times in cold water, depending on the water temperature, are presented in Table 7.3.21

For nonfreezing cold injury (NFCI), slow, gradual rewarming of affected tissues is required, though treatment of coincident hypothermia may take precedence. Pain treatment is very challenging in NFCI, and while surgical or pharmacological sympathectomy may provide short-term relief in severe cases, pain often returns after several months, contraindicating this approach. Unfortunately there are no known medications that are appropriate for treatment of NFCI, beyond those used for symptomatic relief.

MEDICAL SURVEILLANCE

Identification of workers who will work in a cold environment requires: (i) determination of the physical and mental qualifications appropriate to the specific job, (ii) medical evaluation of the individual’s physical and psychological ability to work in the cold, and (iii) identification of specific medical conditions which may be contraindications to working in the cold.1 Conditions that may preclude work in the cold include exertional angina, previous cold injury, asthma, peripheral vascular disease, coronary artery disease, alcohol abuse, use of tranquilizers, and thermoregulatory disorders.

Workers should be excluded from the workplace at −1°C (30.2°F) or below if they are suffering from any of these medical conditions or if they are taking medication which either interferes with normal body temperature regulation or reduces tolerance to work in cold environments.2 Workers who are routinely exposed to temperatures below −24°C (−11.2°F) with wind speeds less than 5 miles/hour, or air temperatures below −18°C (0°F) with wind speeds above 5 miles/hour, should be certified as medically cleared for such exposures.

Risk factors for cold injury are associated with the agent (cold), the host (the individual), or the environment (wind chill, humidity, duration of exposure, amount of activity, and protective clothing). A decrease in the equivalent chill temperature and working with cold metal objects or super-cooled volatile liquid fuels, which conduct heat away from the skin very rapidly, increase the risk of cold injury to unprotected skin. There is significant variation in individual susceptibility to cold injury. Several individual risk factors for cold injury have been identified.13,21 While there is a lack of data in civilian populations, data from the US military indicates that women and African Americans may be at increased risk.22 Poor physical condition, fatigue, age (the very young and the very old), inadequate caloric intake, acute or chronic illness (e.g., angina or cardiovascular disease), and a previous cold injury are additional risk factors associated with an increased risk of cold injury. Frostbite is the most frequently occurring cold injury, occurring in 40–50% of all cases.23

Alcohol, stimulants, and prescription drugs also affect the body’s cold adaption mechanisms. Alcohol impairs judgment and reduces awareness of the signs and symptoms of cold injury. It produces peripheral vasodilation, which interferes with peripheral vasoconstriction, increasing body heat loss. Alcohol also increases urine output, exacerbating dehydration. Caffeine may have similar effects on blood vessels and urine production. Nicotine increases the risk of a peripheral cold injury by increasing the degree of peripheral vasoconstriction, which increases the rate of skin cooling and heat loss to the environment. The use of major tranquilizers (e.g., phenothiazines) also increases the risk of cold injury. Chlorpromazine suppresses peripheral shivering and produces vasodilation.19

PREVENTION

Cold injuries may be prevented by properly protecting workers from a cold environment through the use of appropriate protective clothing and shelter. All workers should be trained in the proper use of protective clothing. The selection of the proper clothing system for a cold environment is based on the principles of insulation, layering, and ventilation.10 Insulation depends on clothing thickness, the properties of the material, and the amount of dead-space air trapped within the garment.22 The inner layer of clothing, such as polypropylene, should wick moisture to the outer layers. The intermediate layers, such as wool or Thinsulate, provide insulation and may be increased or decreased for appropriate warmth. The outer layer, such as Gor-Tex, should be wind resistant and water repellent and allow water vapor and moisture, generated as perspiration, to pass through the layer. The outer layer should also be easily vented to release body heat and to prevent sweating and to allow the evaporation of moisture if sweating does occur.

A similar layering system should be used to protect the head, hands, and feet. Gloves should be worn. If fine manual dexterity is required, thin inner gloves may be worn under heavier outer gloves or mittens. The outer gloves may be temporarily removed as needed. The head should be protected, since 30% of body heat is lost through the head. Workers at increased risk of cold injury may require additional clothing.

When wearing cold weather clothing, the mnemonic “COLD” should be used to guide appropriate clothing maintenance:

  • Keep clothing Clean to ensure maximum insulation.
  • Avoid Overheating by adding or removing insulating layers, as appropriate.
  • Wear Loose clothing and in Layers to allow free blood circulation, trap dead-space air, and adapt to changes in the workload or environment.
  • Keep clothing Dry to ensure maximum insulation.

Workers should wear anticontact gloves to prevent contact frostbite. For work performed at temperatures below −7°C (19.4°F), a warning or safety briefing should be given at least daily to each worker by the supervisor to prevent inadvertent contact of bare skin with cold surfaces. If the air temperature is −17.5°C (0°F) or less, the hands should be protected by mittens. Workers handling evaporative liquids (gasoline, alcohol, or cleaning fluids) at air temperatures below 4°C (39.2°F) should take special precautions. Workers handling liquefied gases (liquid natural gas, liquid oxygen, and liquid nitrogen) must also take special precautions, particularly in the event of a spill.

Special protection of the hands is required to maintain manual dexterity. If fine work is to be performed with bare hands for more than 10–20 minutes in an environment below 16°C (60.8°F), special provisions should be established for keeping the workers’ hands warm. Metal handles should be covered by thermal insulating material at temperatures below −1°C (30.2°F). In the absence of extenuating circumstances, cold injury to body parts other than the hands, feet, and/or head is not likely to occur without showing the initial signs and symptoms of hypothermia.

Prevention of non-freezing cold injury centers on proper foot care, including keeping the feet dry and allowing proper circulation. Vapor barrier boots, which are very effective in keeping moisture out, present a double-edged sword, as they also retain fluid from sweat or that accumulated inside the boot due to leaks or dripping. Socks should be changed whenever they become wet, and feet should not remain motionless.

If available clothing does not provide adequate protection against the cold, work should be modified or suspended until adequate clothing is available or until weather conditions improve. If clothing is wet, workers should immediately change into dry clothing. If work is done at normal temperatures prior to entering a cold area, it may be necessary for the worker to change clothing that is damp due to sweating.

Shelter is used to reduce exposure to the cold, when periodic rewarming breaks must be taken. Workers must be encouraged to drink fluids at regularly scheduled times to avoid dehydration. Fluid intake should increase with decreasing temperature and increasing levels of exertion. Warm, sweet drinks, and soups provide calories and fluid volume. Caffeine has a minor diuretic effect,23 so coffee intake should be moderated, though the warming and stimulant effects may be desirable, and alcohol use is contraindicated.

Protective eyewear should be used to protect against blowing snow and ice crystals, airborne particulates, ultraviolet radiation, and glare. Sunscreen will prevent sunburn, and moisturizers will reduce the effects of dry cold on the skin, lips, and nose. Self-aid and “buddy” aid, with frequent checks, should be used to identify early signs and symptoms of cold injury.

Additional workplace requirements exist for refrigerator rooms, working with toxic substances, and exposure to vibration.

Health and safety education on the recognition and treatment of cold injuries should be provided to workers. Training should be performed on how to wear and work in cold weather clothing. Workers should also be instructed in safety and health procedures such as proper rewarming methods, appropriate first aid treatment, good clothing practices, eating and drinking requirements, recognition of impending frostbite and hypothermia, and safe work practices. New employees should be allowed to become accustomed to working conditions in the cold and use of the required protective clothing. The weight and bulkiness of clothing should be included in estimating the required work performance. For work at or below −12°C (10.4°F) equivalent chill temperature, there should be constant protective observation (“buddy” system or direct supervision). The work rate should not be so high as to cause heavy sweating that will result in wet clothing, and there should be frequent rest periods. Most important of all, the worker must respect and use common sense in dealing with the cold.

References

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  10. 10. Department of the Army. Prevention and Management of Cold-Weather Injuries. Washington, DC: Headquarters, DA; 2005.
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  12. 12. Candler WH, Ivey H. Cold weather injuries among US soldiers in Alaska: a five-year review. Mil Med 1997;162:788–91.
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Notes

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