boiling hot vs smouldering

boiling hot

adj
  • Extremely hot (having a high temperature: of an object, the weather, a living creature) 

smouldering

adj
  • Burning slowly, producing smoke but no flame. 

noun
  • The act by which something smoulders; residual heat. 

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