Quick! Hot spicy food going cold — out of bed! (5,2)
I believe the answer is:
hurry up
'quick' is the definition.
'hot spicy food going cold out of bed' is the wordplay.
'hot' becomes 'h'.
'spicy food' becomes 'curry'.
'going' indicates named letters should be taken away.
'cold' becomes 'c' (eg on taps).
'out of bed' becomes 'up' ('up' can be a synonym of 'out of bed').
'curry' with 'c' removed is 'urry'.
'h'+'urry'+'up'='HURRY UP'
(Other definitions for hurry up that I've seen before include "Make haste" , "Get a move on!" , "Be quick" , "Run" .)