What condition involves local cooling of the body, leading to blue and blotchy skin?

Frostbite is the correct answer as it specifically refers to the local cooling of body tissues, usually due to exposure to freezing temperatures. This results in the freezing of skin and underlying tissues, commonly affecting extremities like fingers, toes, ears, and the nose. The affected area can exhibit symptoms such as a pale or bluish color and may appear blotchy as the tissue loses its blood supply and begins to damage.

In contrast, hypothermia involves a general drop in body temperature, affecting the entire body rather than just specific areas, and while it can also lead to changes in skin coloration, the characteristic bluish blotches are not a defining symptom. Heat exhaustion is related to prolonged exposure to high temperatures and results in symptoms like heavy sweating, weakness, and a wet skin condition, not cooling and blue skin. Dehydration, on the other hand, is characterized by a loss of body fluids and electrolytes, leading to symptoms like thirst and dry skin, but it does not cause local cooling or specifically bluish blotches.