It may not be implemented, or I may just not be able to figure it out.
But why can a sheet not be broken down into rags? Quite a few bits of clothing won’t break down to anything, and rags are quite rare (as far as I have seen). This makes creating bandages quite difficult. And is it possible to create first aid kits?
Hammers. I’ve wanted to build a wall and a door. I have the lumber, I have the nails but a hammer cannot be found. I cannot find a hardware store and no other building seems to wield a hammer or hatchet. I think it would be helpful if hammers spawned inside some houses, along with screwdrivers, etc. On top of that why can I not use a rock (with a penalty) to bang nails? I believe one crafting recipe allows a rock to be used instead of a hammer, but most do not.
For an added challenge, on top of a temperature system, there could be a cleanliness system. Find a tub and take a quick bath, maybe find some soap. Morale could suffer the longer you go without bathing, plus your smell could linger longer and be easier to track. Bathing could greatly raise morale, temperature, and could even clean clothes for getting rid of scent and penalties to encumbering limbs (built up dirt, etc).