During a short rest, you may scavenge materials and make 1 bow a set of 5 arrows (these count as "1 item" for the purpose of Improvised Items), general supplies. They are improvised. Only common mundane items can typically be made in this way, but the GM may specify if other options are available to you.
An improvised item is one made out scrap or temporary pieces. It functions like any other item, but only exists for 8 hours before falling apart and becoming destroyed. It is easy to tell whether an item is improvised. Interacting with an item is enough to determine if it is improvised or not.