Use a bigger chest. Or a lockbox. If I find a lockbox, I tend to put anything and everything fragile that I really don't want to have breaking/burning inside. Things like scrolls waiting to be cloned, wands of fireball, holy hand grenades, etc...
Bigger chests also provide more protection than small ones. If for any reason you are carrying around more than 6 small chests, you might as well dump them for a medium-sized one. More storage, more protection, same weight. Still, at that point, you're carrying 15kg around, of just chest, not even counting whats inside, so there's that...
If you're carrying around enough chests to where it would be more efficient to put everything in a large chest, you maybe should get rid of some stuff.
EDIT: I seem to be having trouble doing things today.
"Put more stuff in the... thing where... more stuff goes in."