use head

use (one's) head

To use one's own intelligence and intellectual ability; to think logically and rationally. In this phrase, "head" refers to one's brain. Often said as an imperative. Come on, Dean, I know you can figure this out on your own. Use your head for a change! We'll have to use our heads if we're going to have any hope of solving this supply issue.
See also: head, use
Farlex Dictionary of Idioms.

use one's head

 and use one's noggin; use one's noodle
Fig. to use one's own intelligence. (The words noggin and noodle are slang terms for "head.") You can do better in math if you'll just use your head. Jane uses her noggin and gets things done correctly and on time. Yes, she sure knows how to use her noodle.
See also: head, use
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (from) top to toe
  • (one's) day in court
  • be on (one's) pat
  • (there's) no peace/rest for the wicked
  • at (one's) doorstep
  • at doorstep
  • (one's) jig is up
  • at will
  • at somebody's expense
  • at (one's) expense
References in periodicals archive
"Reagan went to the docs today and we were advised to use Head and Shoulders CLASSIC as a bubble bath to sooth the spots.