Frostbite is a type of injury in which extreme cold damages the skin and the tissues beneath it.
Extreme cold can cause a range of injuries and conditions, including frostnip, chilblains, frostbite, hypothermia, and trench foot.
Frostbite can cause permanent physical damage and might even lead to amputation.
In this article, we explain the symptoms, causes, and possible treatments for frostbite.
What is frostbite?
Frostbite occurs in extremely cold temperatures or after prolonged exposure to freezing conditions.
In extremely cold temperatures, or if a person experiences exposure to freezing conditions for an extended period, blood flow to certain parts of the body can drop to dangerously low levels. Such body parts include the fingers, toes, hands, and feet.
When parts of the body do not receive enough oxygen-rich blood, the cells and tissues may die.
At freezing point, which is 32 degrees Fahrenheit (ºF), or zero degrees Celcius (ºC), a person might begin to feel pain after just a few seconds. This pain is probably caused by frostnip, which refers to the early stages of frostbite. Wet conditions can make it worse.
When temperatures drop to freezing, the blood vessels near the surface of any exposed skin start to narrow in an attempt to preserve heat at the center of the body.
Tiny blood clots might occur as circulation decreases. The tissues and fluids in the affected part may freeze, causing soft tissue to die. Gangrene may result, possibly leading to amputation.
The physical damage from frostbite can be severe and long-lasting.
Frostbite can affect any part of the body but usually occurs on the hands, ears, feet, nose, and lips.
According to the Centers for Disease Control and Prevention (CDA), there were 16,911 deaths due to extreme cold between 1999 and 2011 in the United States. However, not all of these deaths were frostbite-related.
Doctors categorize frostbite in degrees depending on severity in a similar way to burns.
First-degree frostbite, or frostnip
This only affects the surface of the skin.
Early symptoms are pain and itching. The skin then develops white or yellow patches and may become numb. Due to its surface-level impact, frostnip does not usually cause permanent damage.
However, an area of skin with first-degree frostbite may lose sensitivity to heat and cold for a short period.
This may cause the skin to freeze and harden but does not affect the deep tissues.
After 2 days, purple blisters may develop in areas that froze. These blisters may turn black and become hard, taking 3–4 weeks to heal.
A person with second-degree frostbite who has nerve damage might experience numbness, pain, or total loss of sensation in the area. The decreased sense of heat and cold may be permanent.
Third- and fourth-degree frostbite