School clothing always very hot (8)
I believe the answer is:
feverish
'very hot' is the definition.
'school clothing always' is the wordplay.
'school' becomes 'fish' (group of fishes).
'clothing' indicates putting letters inside (some letters cover up or clothe others).
'always' becomes 'ever' (synonyms).
'fish' placed around 'ever' is 'FEVERISH'.
(Other definitions for feverish that I've seen before include "Frenzied" , "restless state" , "Nervously excited" , "hectic" , "Suffering from a high temperature" .)