Non-freezing cold injury

Non-freezing cold injuries (NFCI) is a class of tissue damage caused by sustained exposure to low temperature without actual freezing.

NFCI is caused by microvascular endothelial damage, stasis and vascular occlusion and is characterised by peripheral neuropathy.

[2][3] NFCI generally affects the hands or feet during exposure to temperatures just above freezing, often wet, and is typically found in soldiers.

[4] Initially the affected area is cold and numb, but this changes to hyperemia (changes to blood flow) within a day or two, along with an intense, painful, burning sensation, blisters, redness, and in some cases ulceration.

[2][1] Strategies to reduce the impact of the condition focus on recognition of those at risk, limiting exposure, and use of suitable personal protective equipment.

[6] Types of NFCI: Four distinct stages occur: Short-term complications can include infection of the affected area and gangrene.

[5] NFCI is caused by microvascular endothelial damage, stasis and vascular occlusion, and generally affects the hands or feet during exposure to temperatures just above freezing, often wet.

[2] Risk factors include exposure of the extremities to cold 0 to 15 °C (32 to 59 °F) and wet for prolonged periods, usually two to three days or longer, but the duration is relative to the temperature, and cases have been reported after immersion in cold sea water 0 to 8 °C (32 to 46 °F) after considerably shorter exposures, and higher temperatures (up to 21 °C (70 °F) for longer periods (order of 8 days).

Diagnosis may rely on dive history, particularly water temperature, though the quality of insulation and fit of the suit will have an influence on perfusion and heat loss.

Strategies to reduce the impact of the condition focus on recognition of those at risk, limiting exposure, and use of suitable personal protective equipment.

[6] In cases of isolated NFCI the extremities should be allowed to rewarm gradually with rest and elevation of the affected limbs.

[12] NFCI is known as a cause of significant morbidity in military personnel and civilians who work in cold conditions,[4] mountaineers, fishermen, homeless people,[1] and occasionally, underwater divers.