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
and it may feel numb. The top layer of skin
feels hard, but the deeper tissue still feels
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.
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
• Gently loosen or remove constricting
clothing or jewellery that may restrict
• Loosely cover the affected area with
a sterile dressing. Place some gauze
between fingers and toes to absorb
moisture and prevent them from
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