het up - English Oxford Living Dictionaries : @OxfordWords

https://en.oxforddictionaries.com/definition/het_up

adjective

informal

• predicative Angry and agitated.
  

  ‘her husband is all het up about something’

Origin

Mid 19th century: from dialect het ‘heated, hot’, surviving in Scots and northern English dialect.

Pronunciation

het up

/hɛtˈʌp/