Prepared to encase the man in ice (5)
I believe the answer is:
sheet
'ice' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'prepared to encase the man in' is the wordplay.
'prepared' becomes 'set' (set up or ready).
'to encase the man' becomes 'he' (I am not sure about this - if you are sure you should believe this answer much more).
'in' means one lot of letters goes inside another.
'set' enclosing 'he' is 'SHEET'.
Can you help me to learn more?
(Other definitions for sheet that I've seen before include "Mattress cover" , "Item of bed linen like these" , "Page of postage stamps" , "Piece of linen, paper, etc" , "leaf" .)