Tie cold and warmth together (4,4)
I believe the answer is:
dead heat
'tie' is the definition.
(I know that dead heat is a type of tie)
'cold and warmth together' is the wordplay.
I cannot quite see how this works, but
'cold' could be 'dead' (similar in meaning) and 'dead' is found in the answer.
'warmth' could be 'heat' (synonyms) and 'heat' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dead heat that I've seen before include "Race result in which two competitors finish exactly even" , "A draw in race, competitors finish exactly even" , "no decisive result" , "so exciting a race?" , "Where runners are equal first" .)