Leaves survive when temperature is higher (5)
I believe the answer is:
exits
'leaves' is the definition.
('exit' can be a synonym of 'leave')
'survive when temperature is higher' is the wordplay.
'survive when' becomes 'ex' (I can't justify this - if you can you should believe this answer much more).
'temperature' becomes 't' (abbreviation).
'higher' indicates anagramming the letters (I've seen 'high' mean this (can mean drunk or on drugs and hence disordered)).
't'+'is'='tis'
'tis' with letters rearranged gives 'its'.
'ex'+'its'='EXITS'
Can you help me to learn more?
(Other definitions for exits that I've seen before include "Goes out, leaves" , "Leaves the stage" , "Departs" , "Ways out" , "Withdraws" .)