Preliminary contest (4)
I believe the answer is:
heat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">preliminary contest</span>' is the definition.<br/ ><span class="explanation-format__explanation">(qualifying stage in a sports contest)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for heat that I've seen before include "It's measured in therms" , "Get agitated" , "Hotness" , "brings out a sweat?" , "Toast" .)