Burns are classified in three different severities.
First degree burns affect only the outer layer of the skin and cause
redness and sensitivity. Second degree burns go deeper into the skin
reulting in blistering, acute pain and redness. Third degree burns
destroy the thickness of the skin and possibly the underlying tissues.
Surprisingly, third degree burns, despite their severity, have little
or no pain assoiciated with them because the nerves in the skin have
been severely damaged.