Burn boxes turned off platform (8)
I believe the answer is:
scaffold
'platform' is the definition.
(scaffold is a kind of platform)
'burn boxes turned off' is the wordplay.
'burn' becomes 'scald' (scald is a kind of burn**).
'boxes' is an insertion indicator (the outside letters must 'box' inside letters in).
'turned' is an anagram indicator.
'off' is an anagram of 'ffo'.
'scald' enclosing 'ffo' is 'SCAFFOLD'.
(Other definitions for scaffold that I've seen before include "Platform on which criminals were once hung" , "Temporary erection for workmen - gallows" , "Gibbet" , "Execution platform" , "where many died" .)