Warmth (4)
'warmth' is the definition.
(I know that warmth can be written as heat)
This is all the clue.
(Other definitions for heat that I've seen before include "Energy that causes a rise in temperature" , "eliminating round" , "Warmth - gossip mag" , "Apply warmth" , "Level of spice" .)
(Other definitions for temperature that I've seen before include "Degree of hotness" , "Measure of heat" , "Degree of heat" , "Measure of warmth" .)