cool-headed
From Longman Dictionary of Contemporary Englishcool-headedˌcool-ˈheaded adjective CALMnot easily excited or upset We need a quick-thinking, cool-headed person for the job.Examples from the Corpuscool-headed• Winnie picked up her knitting again, determined to remain cool-headed over the whole affair.• Garnett is considered a cool-headed, professional manager.• In fact this might be one of the abiding lessons on the tour; the need for patience and cool-headed skill.