ardor vs warmth

ardor

noun
  • Intense heat. 

  • Great warmth of feeling; fervor; passion. 

  • Spirit; enthusiasm; passion. 

warmth

noun
  • A moderate degree of heat; the sensation of being warm. 

  • Friendliness, kindness or affection. 

  • The effect of using mostly red and yellow hues. 

  • Fervor, intensity of emotion or expression. 

How often have the words ardor and warmth occurred in a corpus of books? (source: Google Ngram Viewer )