Originally posted by Mr B.:

They are not actually highlighted are they? Not when you open up inventory.

Might add something to suggestions.

If you use MaddogDino suggestion and select bow and arrow type, the hotkeys displayed for me during combat and the arrow in use and bow were both highlighted. Had wooden on 2 and fire on 1. Hit 1 and fire arrows highlighted. My pickaxe and hammer had been in 1 and 2 slots. Put them in regular inventory. Have to open inventory to use those. There not combat required so better to put arrows up top. Situational of course.