Green’s Dictionary of Slang

(US) angry, emotional.

1893		St Louis Post-Dispatch (MO) 3 Dec. 17/7: ‘To get red-headed’ is to get angry.
1909		J. Washburn Und. Sewer 189: They are society dudes [...] they pinch and hurt the girls just to hear them scream, and curse and call them names, if they try to protect themselves; this produces a ‘red-headed’ effect upon all of us.
1924		C.S. Montanye ‘The Might That Failed’ in Top Notch 1 Apr. 🌐 That stuff you wrote yesterday hasn’t helped your popularity any with Finnegan and the bunch inside. In fact, I understand Brannigan is slightly red-headed because of it.
1953		‘John Monahan’ [W.R. Burnett] Big Stan 110: ‘With you [things] don’t slip, Stan. [...] You don’t get redheaded about things. You’re calm’.