The Collaborative International Dictionary of English v.0.48:

Calefaction \Cal`e*fac"tion\, n. [L. calefactio: cf. F.
   cal['e]faction.]
   1. The act of warming or heating; the production of heat in a
      body by the action of fire, or by communication of heat
      from other bodies.
      [1913 Webster]

   2. The state of being heated.
      [1913 Webster]

WordNet (r) 3.0 (2006):

calefaction
    n 1: the property of being warming [syn: calefaction,
         incalescence]