Visual determination of tissue viability is difficult in first few weeks; classify early injuries as superficial or deep
Substantial edema over 4-6 hours; skin blisters form within 6-24 hours; Desquamate and form hard black eschars over several days
Frostbite
Generalized
Le Fort fractures
Hypothermia
Shark bite
Freezing
Nasal fracture
Nailbed laceration