I would never believe in a million years that guys in our line of work would literally need to engage anyone else's opinion on what BAG to use that can carry stuff from one place or another.
In the above example I don't think the message "I AM AWESOME AND A FIREFIGHTER FIREFIGHTER FIREFIGHTER" is broadcast quite loud enough.
I suggest you double bag- just in case one bag is lost at least you still have your stuff in another bag that proclaims your awesomesauceness.
AFD / FOD
"Because sometimes what they know CAN hurt you."