cool-headed

[ kool-hed-id ]

/ ˈkulˈhɛd ɪd /

not easily excited; calm.

Origin of cool-headed

First recorded in 1770–80

cool-head·ed·ly, adverb cool·head·ed·ness, noun

Eighteen months ago, I was in a similar situation and had the opportunity to act like a cool-headed adult—but failed miserably.

Warren Buffett’s Cancer Decoded |Kent Sepkowitz |April 19, 2012 |DAILY BEAST
The Colonel, Belmont, and the young Harvard graduate were the three most cool-headed and resourceful members of the party.

A Desert Drama |A. Conan Doyle
For once the brave and cool-headed Dutchmen were fairly panic-stricken.

The Great Boer War |Arthur Conan Doyle
She was jealous of her reputation with the old and cool-headed lords about her.

The Town |Leigh Hunt

He made such efforts as all cool-headed people make, to buffet the inexplicable, and to resist an unreasonable impression.

A Singular Life |Elizabeth Stuart Phelps
My advice is to keep quiet and cool-headed, and I feel almost certain you won't be interfered with.

Looking Seaward Again |Walter Runciman