Hot or warm (7)
I believe the answer is:
thermal
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">hot</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">warm</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ ></span>
(Other definitions for thermal that I've seen before include "Pertaining to heat" , "Upward current of warm air" , "Up-current of air" , "Related to heat" , "type of baths" .)