What medical condition results from tissues freezing due to extreme cold?

Frostbite is the medical condition that occurs when skin and other tissues freeze due to exposure to extreme cold. This condition primarily affects body parts that are more susceptible to cold, such as fingers, toes, and the nose. The freezing process can lead to damage of the skin and underlying tissues. Symptoms include numbness, discoloration of the skin (which may appear pale or blotchy), and in severe cases, blistering or skin necrosis can occur.

In contrast, hypothermia is a more systemic reaction to cold, where the body loses heat faster than it can produce it, leading to a drop in core body temperature. Frost nip is a milder form of frostbite that typically affects the skin's surface and does not cause permanent damage. Chilblains, on the other hand, are painful inflammations of small blood vessels in the skin that occur in response to repeated exposure to cold but above freezing temperatures, leading to itching and swelling without the freezing of tissues. Thus, frostbite specifically describes the freezing of tissues, making it the correct answer.