Possible Clues:

• That might make one a little heated, as a matter of course
• A soft drink may have one
• Unit often burned off
• A learner in cold Oxford college ultimately denied a bit of heat
• 10 up in the clear with the food
• Unit of heat (concerned with diet)
• A collier heartlessly made to work, generating a bit of heat
• A recoil (anag.)
• The measure to which coal gets heated with ire
• Unit of energy in foods