Temperature rising in sweaty journalist's wool clothing (6)
I believe the answer is:
tweeds
'wool clothing' is the definition.
(clothes made from tweed)
'temperature rising in sweaty journalist's' is the wordplay.
'temperature' becomes 't' (abbreviation).
'rising' says the letters should be written in reverse (going up in a down clue).
'in sweaty' becomes 'ew' (I can't justify this - if you can you should give a lot more credence to this answer).
'journalist's' becomes 'ed's' (short for editor).
'ew' written backwards gives 'we'.
't'+'we'+'eds'='TWEEDS'
(Other definitions for tweeds that I've seen before include "garments" , "clothing items" , "Sensible clothing" , "Country wear" , "Country clothes" .)