ENGLISH
REFERENCE

set one's hair on fire

idiom
Meaning

To become wildly impassioned; to behave crazily.


Origin

disputed origin

Possibly from stories of Viking marauders said to have set their hair and beards on fire when running into battle in order to appear fanatical and fearsome.

Examples
SIMPLE

He sets his hair on fire whenever he loses a game.

CONTEXTUAL

The manager set his hair on fire when he saw the budget report, demanding immediate changes from the entire team.

COMPLEX

Rather than calmly addressing the minor error, the director set his hair on fire and insisted that the entire project be scrapped immediately.

Anchors to
Related idioms8entries
  1. 01

    abound in one's own sense

    To follow one’s own inclinations and opinions.

  2. 02

    ace up one's sleeve

    A surprise advantage of which others are not aware.

  3. 03

    act one's age

    To behave in a manner appropriate to one's age.

  4. 04

    act one's age, not one's shoe size

    Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).

  5. 05

    add fuel to the fire

    To worsen a conflict between people; to inflame an already tense situation.

  6. 06

    afraid of one's own shadow

    Exceptionally timid.

  7. 07

    air one's dirty laundry in public

    To reveal one's sordid secrets to the public.

  8. 08

    air one's dirty linen in public

    Synonym of air one's dirty laundry in public.

Last updated July 12, 2026