Very cold press employee introducing cipher (7)
I believe the answer is:
subzero
'very cold' is the definition.
(I've seen this before)
'press employee introducing cipher' is the wordplay.
'press employee' becomes 'sub' (subeditor).
'introducing' means one lot of letters go next to another.
'cipher' becomes 'zero' ('zero' can be a synonym of 'cipher').
'sub'+'zero'='SUBZERO'
(Other definitions for subzero that I've seen before include "Extremely nippy" , "Negative" , "very cold" , "Below freezing point" , "Colder than freezing" .)