set one's hair on fire
To become wildly impassioned; to behave crazily.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He sets his hair on fire whenever he loses a game.”
“She sets her hair on fire every time she finds a spider.”
“The manager set his hair on fire when he saw the budget report, demanding immediate changes from the entire team.”
“You do not need to set your hair on fire just because the flight is delayed by twenty minutes.”
“The activists set their hair on fire during the meeting to protest the new city laws regarding public housing.”
“My neighbor sets his hair on fire every time a delivery driver parks for a few seconds in front of his driveway.”
“Rather than calmly addressing the minor error, the director set his hair on fire and insisted that the entire project be scrapped immediately.”
disputed origin
The expression is said to have its origins in the conduct of Viking marauders. According to popular but unproven stories, these warriors would set their own hair and beards on fire before running into battle. The intention was to appear both fanatical and fearsome to their opponents, a tactic that prioritized psychological impact over the preservation of one's follicles.
- 01
abound in one's own sense
To follow one’s own inclinations and opinions.
- 02
ace up one's sleeve
A surprise advantage of which others are not aware.
- 03
act one's age
To behave in a manner appropriate to one's age.
- 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”).
- 05
add fuel to the fire
To worsen a conflict between people; to inflame an already tense situation.
- 06
afraid of one's own shadow
Exceptionally timid.
- 07
air one's dirty laundry in public
To reveal one's sordid secrets to the public.
- 08
air one's dirty linen in public
Synonym of air one's dirty laundry in public.
Last updated August 10, 2026