Cold-weather warfare
Trench foot is a medical condition caused by prolonged exposure of the feet to damp, unsanitary, and cold conditions at temperatures as warm as for as few as 13 hours. Exposure to these environmental conditions causes deterioration and destruction of the capillaries and leads to morbidity of the surrounding flesh. Affected feet may become numb, affected by erythema (turning red) or cyanosis (turning blue) as a result of poor blood supply, and may begin emanating a decaying odour if the early stages of necrosis (tissue death) set in. As the condition worsens, feet may also begin to swell. Advanced trench foot often involves blisters and open sores, which lead to fungal infections. If left untreated, trench foot usually results in gangrene, which may require amputation. If trench foot is treated properly, complete recovery is normal, though it is marked by severe short-term pain when feeling returns. Trench foot affected tens of thousands of soldiers engaged in trench warfare in World War I. Keeping feet warm and dry, or at least changing into warm and dry replacement footgear, is the best way to avoid trench foot.
Treatment of equine lameness
“Firing”, or thermal injury, includes thermocautery and cold firing. In both cases, firing is performed after the initial inflammation associated with the injury has subsided. The horse is sedated, and the area is clipped and blocked with a local anesthetic. The most common form of firing is “pin firing”, which uses a specialized machine with a hot tip to penetrate through the skin and into the tendon or periosteum. Multiple applications are applied in rows over the site of injury. As expected, horses require analgesia following this procedure. Uses for pin firing include tendonitis, suspensory desmitis, sesamoiditis, splints, curbs, and other soft-tissue injuries. Cold firing is a method similar to pin firing, but uses liquid nitrogen to produce its effects. It is often used to treat lameness associated with the bone, such as sore shins or splints, and usually only after other treatments have failed. Firing forces rest of an injury, and while some argue this is the true reason it leads to any improvement of lameness, others contest that undeniable success in its use has been seen. Pin firing is not taught in veterinary schools in present day.