Warm up (4)
'warm up' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for heat that I've seen before include "Level of spice" , "Warmth - gossip mag" , "Cook" , "Energy that caues a rise in temperature" , "Warm up" .)
'warm up' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for get ready that I've seen before include "Prepare oneself" , "third of three" .)