As I was perusing this thread, I was hoping to god someone would mention "wiping" the stretcher down. Not that everyone else doesn't do this, of course!
It blows my mind that anyone would reuse a sheet, let alone a blanket, pillowcase, etc. The pillows, stretcher, and mattress can be cleansed with cavi-wipes, but linens must be changed.
As Jake said, most hospitals, at least in my area, provide pillowcases, sheets, and blankets for 911 agencies, to "swap" them out. There is no reason to reuse linens. Event he convalescent agencies are allowed to swap. Also, Virginia requires ambulances to stock a certain number of sheets, blankets, pillows, and pillow cases on all ground ambulances. I would think other states do as well?
If I remember correctly, we're required to have 4 sheets, 2 pillow cases, 2 blankets, 2 towels, 2 pillows, minimum.
Hypothetically, I can just imagine my previous patient (84 y/o CHF'r) leaning over and asking my current patient (22 y/o Benzo OD), if he/she would like to share a blanket.