Definition of "caloricity"

At first she "ran a temperature" in American parlance, and I could not resist the exquisite caloricity of unexpected delights—Venus febriculosa—though it was a very languid Lolita that moaned and coughed and shivered in my embrace.

1955, Vladimir Nabokov, chapter 12, in Lolita, 1st American edition, New York, N.Y.: G[eorge] P[almer] Putnam’s Sons, published August 1958, part 2, page 200