Cold Link Africa July/August 2019 | Page 37

FEATURE INCORPORATING COLD CHAIN Avoiding refrigeration injuries By: Grant Laidlaw of ACRA We look at how to safely operate (and avoid any injuries) within the refrigerated environment inside a cold room and/or freezer. RISKS OF EXPOSURE loss of body heat and the consequent lowering of the inner core temperature (internal temperature of the body). Hypothermia can be fatal. Immersion foot: When working in a cold room without the correct waterproof footwear, you stand the chance of developing immersion foot. Immersion foot occurs in individuals whose feet have been wet, but not freezing cold, for days or weeks. It can occur at temperatures up to 10°C. The primary injury is to nerve and muscle tissue. Symptoms include tingling and numbness, itching, pain, swelling of the legs, feet or hands, and even blisters. The skin may be red initially and turn to blue or purple as the injury progresses. In severe cases, gangrene may develop. What are the health effects of exposure to cold and wet conditions found in cold room and freezer room environments? Cooling of body parts may result in various cold injuries – non-freezing injuries and freezing injuries – and hypothermia, which is the most serious. Non-freezing cold injuries include chilblains, immersion foot and trench foot. Frost-nip and frostbite are freezing injuries. Toes, fingers, ears and nose are at greatest risk because these areas do not have major muscles that produce heat. In addition, the body will preserve heat by favouring the internal organs and therefore reduce the flow of blood to the extremities under cold conditions. Hands and feet tend to get cold more quickly than the torso because: • they lose heat more rapidly since they have a higher surface area-to- volume ratio; and • they are more likely to be in contact with colder surfaces than other parts of the body. EXAMPLES OF ‘FREEZING’ INJURIES If the eyes are not protected with goggles in high wind chill conditions, the corneas may freeze. The most severe cold injury is hypothermia, which occurs from excessive Frost-nip is the mildest form of a freezing cold injury. It occurs when ear lobes, noses, cheeks, fingers or toes are exposed to the cold and the top layers of the skin freeze. The skin of the affected area turns white Trench foot: This is ‘wet, cold disease’ resulting from prolonged exposure to a damp or wet environment from above the freezing point to about 10°C. Depending on the temperature, an onset of symptoms may range from several hours to many days, but the average is three days. Trench foot is more likely to occur at lower temperatures whereas an immersion foot is more likely to occur at higher temperatures and longer exposure times. A similar condition of the hands can occur if a person wears wet gloves for a prolonged period under cold conditions described above. Symptoms are similar to immersion foot. and it may feel numb. The top layer of skin feels hard, but the deeper tissue still feels normal (soft). Frost-nip can be prevented by wearing warm clothing and footwear. It is treated by gentle re-warming (such as holding the affected tissue next to unaffected skin of the victim or of another person). As for all cold-induced injuries, never rub the affected parts, becauseice crystals in the tissue could cause damage if the skin is rubbed. Do not use hot objects such as hot water bottles to re-warm the area or person. Frostbite is a common injury caused by exposure to extreme cold or by contact with extremely cold objects (especially those made of metal). It may also occur in normal temperatures from contact with cooled or compressed gases. Frostbite occurs when tissue temperature falls below the freezing point (0°C), or when blood flow is obstructed. Blood vessels may be severely and permanently damaged and blood circulation may stop in the affected tissue. In mild cases, the symptoms include inflammation of the skin in patches accompanied by slight pain. In severe cases, there could be tissue damage without pain, or there could be burning or prickling sensations resulting in blisters. Frostbitten skin is highly susceptible to infection and gangrene (local death of soft tissues due to loss of blood supply) may develop. W hen it comes to avoiding issues of hypothermia in particular, it’s important that staff attend a first aid course that specifically deals with hypothermia. In addition, the compulsory, legislated ‘Safe handling of refrigerants’ course should be completed by each staff member working with refrigerants. This course includes aspects of hypothermia. Having said that, let us look into this subject, including the basic first aid aspects. PPE such as a thermal suit is vital for protection in freezer environments. • • First aid for frostbite, as well as immersion or trench foot, includes: • If possible, move the victim to a warm area. • Gently loosen or remove constricting clothing or jewellery that may restrict circulation. • Loosely cover the affected area with a sterile dressing. Place some gauze • • • between fingers and toes to absorb moisture and prevent them from sticking together. Quickly transport the victim to an emergency care facility. DO NOT attempt to re-warm the affected area on site (but do try to stop the area from becoming any colder). Without the proper facilities, tissue that has been warmed may refreeze and cause more damage. DO NOT rub area or apply dry heat. DO NOT allow the victim to drink alcohol or smoke. Seek medical attention. Hypothermia usually occurs when body temperature falls below 33°C and can be fatal. COLD LINK AFRICA • July/August 2019 37