Remember 'use your head' emphasizes thinking systematically to resolve complex issues. Faced with a broken car engine, she had to use her head to find a solution.
Pro Tip 2/3
Non-literal
'Use your head' is metaphorical, meaning to apply mental effort, not physical. You can't open that lock by force, you need to use your head.
Pro Tip 3/3
Judgement Call
This phrase is often used when a decision requires discernment, not just common sense. Deciding who to hire, the manager told the team to use their heads.