Cold injuries range from frostnip to frostbite (see Table 18.2). History should focus on exposure temperature, duration, wind velocity, clothing, and underlying comorbidities. Distal areas are always affected first, which usually include fingers, toes, extremities, nose, and ears and even the cornea. Caretakers should focus on vital signs, assessment of the degree of hypothermia, and resuscitation. Retained sensation, normal skin color, and clear fluid within blisters (if present) indicate positive prognosis. Nonblanching cyanotic, firm skin, and dark fluid-filled blisters indicate poor prognosis. Risk factors include extremes of age, homelessness, altered mental status (drug/alcohol use, head trauma), nicotine or other vasoconstrictive drug use, preexistence of peripheral vascular disease, and diabetes.