High temperature (5)
'high temperature' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for fever that I've seen before include "Reason for temperature" , "Nervous excitement, high temperature" , "Masefield's desire for the sea" , "A rise in the temperature from infection" , "Elvis hit" .)
'high temperature' is the definition.
(synonyms)
This is all the clue.
(Other definitions for heat that I've seen before include "Warmth - passion" , "Preliminary round in a contest" , "Get agitated" , "Raise temperature" , "Provide warmth" .)