hot water vs trauma centre

hot water

noun
  • A dangerous situation; trouble. 

  • fierce criticism 

  • Used other than figuratively or idiomatically: see hot, water. 

trauma centre

noun
  • A specialized section of a hospital intended to treat suddenly occurring life-threatening injuries and medical conditions. 

  • A type of hospital with a highly capable trauma department. 

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