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.^[1] There are several forms of NFCI, and the common names may refer to the circumstances in which they commonly occur or were first described, such as trench foot, which was named after its association with trench warfare. 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.^[2]

Development may be gradual, and it may be difficult to recognise and treat.^[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. It may have lifelong effects, including numbness, paraesthesia, and chronic pain, the etiology of which is not yet adequately demonstrated. Hypersensitivity to cold may also occur.^[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.^[5]

Symptoms may be similar to those of decompression sickness and hand-arm vibration syndrome, and NFCI may occur in conditions where these are possible or likely – diving in cold water, and logging and construction work in cold environments.