1. Cool Your Jets Today

: One of its earliest recorded uses is in the 1952 novel Stand by for Mars! from the Tom Corbett, Space Cadet series, where a character is told, "Cool your jets, space creep!".

: To advise caution when someone is acting impulsively out of enthusiasm (e.g., "Cool your jets, Sarah. Make sure you have the job offer in writing first."). 1. Cool Your Jets

or Take a chill pill : Modern, very informal ways to say the same thing. : One of its earliest recorded uses is

: Specifically used when someone's anger is "boiling over". Keep your shirt on : An older idiom for staying calm. Pop Culture Connections Space Cadet series

: A classic alternative for advising patience.